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An 8.65-g sample of an unknown group 2a metal hydroxide is dissolved in 85.0 ml of water. an acid-base indicator is added and the resulting solution is titrated with 2.50 m hcl(aq) solution. the indicator changes color signaling that the equivalence point has been reached after 56.9 ml of the hydrochloric acid solution has been added.

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Answer;

The molar mass of metal hydroxide = 121.66 g/ mole

The formula is Sr(OH)2

Explanation;

M(OH)2 + 2 HCl = MCl2 + 2 H2O  

Moles of the acid = 2.5 x 56.9 / 1000 = 0.14225  

Therefore; moles of hydroxide at the eq point = 0.0711 moles  

These have a mass of 8.65g

Thus; mass of 1 mole = 8.65 / 0.0711

         = 121.66 g / mole  

That means the compound is Sr (OH)2 ..

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Which of the following would be considered a solution ? A salt in the sugar bowl B sugar added to water C oil added to water D any fat-soluble substance mixed with water soluble substance

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Which of the following would be considered a solution ? A salt in the sugar bowl B sugar added to water C oil added to water D any fat-soluble substance mixed with water soluble substance

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What volume 12.6 M HCL must be added to enough water to prepare 5.00 litters of 3.00 M HCL?

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To solve this problem, we shall use the role;
M1V1 = M2V2
M1: is the molarity of the solution before dilution.
V1: is the volume of the solution that we need to dilute.
M2: is the molarity of the solution after dilution.
V2: is the volume of the solution after dilution.

By substitution;
12*V1 = 3*5
V1 = 1.25 litters.

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Why was it so important that a Bill of Rights be added to the Constitution?

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Why was it so important that a Bill of Rights be added to the Constitution?

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Owners of a recreation area are filling a small pond with water. They are adding water at a rate of 25 liters per minute. There are 400 liters in the pond to start. Let W represent the total amount of water in the pond (in liters), and let T represent the total number of minutes that water has been added. Write an equation relating W to T . Then use this equation to find the total amount of water after 14 minutes. Equation: Total amount of water after 14 minutes: liters

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Owners of a recreation area are filling a small pond with water. They are adding water at a rate of 25 liters per minute. There are 400 liters in the pond to start. Let W represent the total amount of water in the pond (in liters), and let T represent the total number of minutes that water has been added. Write an equation relating W to T . Then use this equation to find the total amount of water after 14 minutes. Equation: Total amount of water after 14 minutes: liters

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Lara made some chocolate tarts. For every 5 cups of chocolate chips. She added 3 cups of sugar. The ratio of chocolate chips to sugar in Lara's chocolate tarts is

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Lara made some chocolate tarts. For every 5 cups of chocolate chips. She added 3 cups of sugar. The ratio of chocolate chips to sugar in Lara’s chocolate tarts is

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H2SO4 is added to a large beaker of water. How is the solution different from the original water?

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Answer:

The new solution is a homogeneous mixture and will have a lower pH i.e. more acidic.

Explanation:

The solution is different is different in 2 ways:

1) The original water is a pure solution. Water is a polar solvent and so is H2SO4. When the later is added to water it is completely dispersed and results in a solution which is essentially a homogenous mixture of two liquids.

2) Secondly the pH of water is neutral i.e.7. Sulfuric acid (H2SO4) is a strong acid which dissociates completely to release H+ ions in solution. This increases the concentration of H+ ions. Since pH = -log[H+], the pH will decrease making the solution more acidic.

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A gas is located inside a closed container. if the gas is allowed to occupy more volume inside the container, what will happen to the pressure? (note: there is no gas added to the container.)

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A gas is located inside a closed container. if the gas is allowed to occupy more volume inside the container, what will happen to the pressure? (note: there is no gas added to the container.)

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_____ must be added to grains during the enrichment process.

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Answered by answersmine AT 22/10/2019 – 04:46 AM

Iron must be added to grains during the enrichment process. 
In the group of grains belong the following products: white flour, de-germed cornmeal, white bread, and white rice. After processing these products are enriched with iron and certain B vitamins (thiamin, riboflavin, niacin, folic acid).

Post your answer

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What element would you get if three protons were added to Lithium?

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25) Answer is: less metallic and more nonmetallic.

Electronegativity increases from left to right across a period, atoms have tendency to attract electrons.

Electronegativity (χ) is a property that describes the tendency of an atom to attract a shared pair of electrons.

26) Answer is: radioisotope.

Radioisotope has an unstable atomic nucleus and emit energy and particles when it changes to a more stable form.

Francium (Fr) is element with atomic number 87 (87 protons and 87 electrons).

27) Answer is: boils.

Boiling is the temperature at which the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere.

The Celsius scale was based on 0°C for the freezing point of water and 100°C for the boiling point of water at 1 atm pressure.

28) Answer is: endothermic.

There are two types of reaction:  

1) endothermic reaction (chemical reaction that absorbs more energy than it releases, ΔH>0).

2) exothermic reaction (chemical reaction that releases more energy than it absorbs).  

For example, the breakdown of ozone is an endothermic process. Ozone has lower energy than molecular oxygen (O₂) and oxygen atom, so ozone need energy to break bond between oxygen atoms.  

29) Answer is: kinetic.

The average kinetic energy of molecules depends on the temperature.  

As temperature increases, molecules gain more energy from surrounding and move faster.  

Kinetic energy (standard unit is the joule J) depends on speed of the molecule.  

Solid gains kinetic energy to become a liquid and then becomes a gas.

30) Answer is: alpha particles.

This was famous Rutherford’s Gold Foil Experiment: he bombarded thin foil of gold with positive alpha particles.

Rutherford observed the deflection of alpha particles on the photographic film.  

Alpha particles are helium atom particles, consist of two protons and two neutrons.  

According to Rutherford model of the atom: atoms have their charge concentrated in a very small nucleus.  

31) Answer is: highest.

For example, calcium oxide.

Calcium oxide (CaO) has ionic bonds between calcium cations (Ca²⁺) and oxygen anions (O²⁻).

Because it has strong ionic bonds, it has high melting point (around 2600°C).

Ionic bond is the electrostatic attraction between oppositely charged ions (cations and anions).

32) Answer is: a scientific model.

A scientific model is a representation of an idea, an object, a process or a system that is used to describe and explain phenomena that cannot be experienced directly.

33) Answer is: the superscript is mass number and the subscript is atomic number.

Atomic number(Z) is the number of protons, which is characteristic of a chemical element..

Mass number (A) is the total number of protons and neutrons in a nucleus.

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What number should be added to both sides of the equation to complete the square ? x2 + 12x = 11

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Answer:

5 in 0.05 is 10 times greater than 5 in 0.005.

Step-by-step explanation:

To find : In which number does the digit 5 have greater value 0.05 or 0.005 how many times as great is it and how do you know ?

Solution :

According to the place value stem,

Ones      Tenths      Hundredths     Thousandths

 0              0                   5                                           – 0.05

 0              0                   0                        5                 – 0.005

In 0.05 5 is in hundredths place and in 0.005 5 is in thousandths place.

So, 5 in 0.05 is 10 times greater than 5 in 0.005.

As 0.05=5times frac{1}{100}

0.005=5times frac{1}{1000}

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Which option explains why the bill of rights was added to the U.S Constitution

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1. We are all free and equal. We are all born free. We all have our own thoughts and ideas. We should all be treated in the same way.

2. Don’t discriminate. These rights belong to everybody, whatever our differences.

3. The right to life. We all have the right to life, and to live in freedom and safety.

4. No slavery – past, and present. Nobody has any right to make us a slave. We cannot make anyone our slave.

5. No Torture. Nobody has any right to hurt us or to torture us.

6. We all have the same right to use the law. I am a person just like you!

7. We are all protected by the law. The law is the same for everyone. It must treat us all fairly.

8. Fair treatment by fair courts. We can all ask for the law to help us when we are not treated fairly.

9. No unfair detainment. Nobody has the right to put us in prison without a good reason and keep us there or to send us away from our country.

10. The right to trial. If we are put on trial this should be in public. The people who try us should not let anyone tell them what to do.

11. Innocent until proven guilty. Nobody should be blamed for doing something until it is proven. When people say we did a bad thing we have the right to show it is not true.

12. The right to privacy. Nobody should try to harm our good name. Nobody has the right to come into our home, open our letters or bother us or our family without a good reason.

13. Freedom to move. We all have the right to go where we want in our own country and to travel as we wish.

14. The right to asylum. If we are frightened of being badly treated in our own country, we all have the right to run away to another country to be safe.

15. The right to a nationality. We all have the right to belong to a country.

16. Marriage and family. Every grown-up has the right to marry and have a family if they want to. Men and women have the same rights when they are married, and when they are separated.

17. Your own things. Everyone has the right to own things or share them. Nobody should take our things from us without a good reason.

18. Freedom of thought. We all have the right to believe in what we want to believe, to have a religion, or to change it if we want.

19. Free to say what you want. We all have the right to make up our own minds, to think what we like, to say what we think, and to share our ideas with other people.

20. Meet where you like. We all have the right to meet our friends and to work together in peace to defend our rights. Nobody can make us join a group if we don’t want to.

21. The right to democracy. We all have the right to take part in the government of our country. Every grown-up should be allowed to choose their own leaders.

22. The right to social security. We all have the right to affordable housing, medicine, education, and child care, enough money to live on and medical help if we are ill or old.

23. Workers’ rights. Every grown-up has the right to do a job, to a fair wage for their work, and to join a trade union.

24. The right to play. We all have the right to rest from work and to relax.

25. A bed and some food. We all have the right to a good life. Mothers and children, people who are old, unemployed or disabled, and all people have the right to be cared for.

26. The right to education. Education is a right. Primary school should be free. We should learn about the United Nations and how to get on with others. Our parents can choose what we learn.

27. Culture and copyright. Copyright is a special law that protects one’s own artistic creations and writings; others cannot make copies without permission. We all have the right to our own way of life and to enjoy the good things that “art,” science and learning bring.

28. A free and fair world. There must be proper order so we can all enjoy rights and freedoms in our own country and all over the world.

29. Our responsibilities. We have a duty to other people, and we should protect their rights and freedoms.

30. Nobody can take away these rights and freedoms from us.

I’m unsure of what you were asking for specifically.

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Which option explains why the bill of rights was added to the U.S Constitution

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1. We are all free and equal. We are all born free. We all have our own thoughts and ideas. We should all be treated in the same way.

2. Don’t discriminate. These rights belong to everybody, whatever our differences.

3. The right to life. We all have the right to life, and to live in freedom and safety.

4. No slavery – past, and present. Nobody has any right to make us a slave. We cannot make anyone our slave.

5. No Torture. Nobody has any right to hurt us or to torture us.

6. We all have the same right to use the law. I am a person just like you!

7. We are all protected by the law. The law is the same for everyone. It must treat us all fairly.

8. Fair treatment by fair courts. We can all ask for the law to help us when we are not treated fairly.

9. No unfair detainment. Nobody has the right to put us in prison without a good reason and keep us there or to send us away from our country.

10. The right to trial. If we are put on trial this should be in public. The people who try us should not let anyone tell them what to do.

11. Innocent until proven guilty. Nobody should be blamed for doing something until it is proven. When people say we did a bad thing we have the right to show it is not true.

12. The right to privacy. Nobody should try to harm our good name. Nobody has the right to come into our home, open our letters or bother us or our family without a good reason.

13. Freedom to move. We all have the right to go where we want in our own country and to travel as we wish.

14. The right to asylum. If we are frightened of being badly treated in our own country, we all have the right to run away to another country to be safe.

15. The right to a nationality. We all have the right to belong to a country.

16. Marriage and family. Every grown-up has the right to marry and have a family if they want to. Men and women have the same rights when they are married, and when they are separated.

17. Your own things. Everyone has the right to own things or share them. Nobody should take our things from us without a good reason.

18. Freedom of thought. We all have the right to believe in what we want to believe, to have a religion, or to change it if we want.

19. Free to say what you want. We all have the right to make up our own minds, to think what we like, to say what we think, and to share our ideas with other people.

20. Meet where you like. We all have the right to meet our friends and to work together in peace to defend our rights. Nobody can make us join a group if we don’t want to.

21. The right to democracy. We all have the right to take part in the government of our country. Every grown-up should be allowed to choose their own leaders.

22. The right to social security. We all have the right to affordable housing, medicine, education, and child care, enough money to live on and medical help if we are ill or old.

23. Workers’ rights. Every grown-up has the right to do a job, to a fair wage for their work, and to join a trade union.

24. The right to play. We all have the right to rest from work and to relax.

25. A bed and some food. We all have the right to a good life. Mothers and children, people who are old, unemployed or disabled, and all people have the right to be cared for.

26. The right to education. Education is a right. Primary school should be free. We should learn about the United Nations and how to get on with others. Our parents can choose what we learn.

27. Culture and copyright. Copyright is a special law that protects one’s own artistic creations and writings; others cannot make copies without permission. We all have the right to our own way of life and to enjoy the good things that “art,” science and learning bring.

28. A free and fair world. There must be proper order so we can all enjoy rights and freedoms in our own country and all over the world.

29. Our responsibilities. We have a duty to other people, and we should protect their rights and freedoms.

30. Nobody can take away these rights and freedoms from us.

I’m unsure of what you were asking for specifically.

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Imagine tossing a coin: What are your chances for tossing a head? What are your chances for tossing a tail? A coin is tossed 10 times: How many times do you expect to get heads? How many times do you expect to get tails? Using this data for the 10 coin tosses, calculate and record the deviation observed from what you expected using the following formula: The more the experimental results deviate from the expected results, the more the deviation value will approach the value of 1.0. As your results get closer to the expected results, the deviation is smaller and nears the value of 0.0. Interpret the meaning of the deviation value you obtained. A coin is tossed 100 times: How many times do you expect to get heads? How many times do you expect to get tails? Using this data for 100 coin tosses: Calculate the deviation for the 100 tosses. The 100 coin tosses are repeated. The results are added to the results of the first 100 coin tosses. How many times do you expect to get heads out of the 200 tosses? How many times do you expect to get tails out of the 200 tosses? Using this data for the 200 coin tosses: What is the deviation for the 200 tosses? How does increasing the total number of coin tosses from 10 to 100 affect the deviation? How does increasing the total number of tosses from 100 to 200 (or more) affect the deviation? What two important probability principles were established in this exercise? With two coins, both coins are tossed 100 times. How many times do you expect to get 2 heads? How many times do you expect to get 2 tails? How many times do you expect to get one head and one tail? The percent of occurrence is the obtained results divided by the total tosses and multiplied by 100. Using this data for the two coins being tossed 100 times. Calculate the percent occurrence for each combination: What is the percent of occurrence for two heads? What is the percent of occurrence for two tails? What is the percent of occurrence for one head and one tail?

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Answer:

The correct answer is a. Amy: wildlife in or near water = turtles, crayfish, goldfish non-water wildlife = fox, deer, bobcat.

Explanation:

According to the question students were asked to contrast their observations based on the location so according to the location, animals should be differentiated into water animals and land animals.

So turtles, crayfish, goldfish are the wildlife found in or near the water and fox, deer, bobcat are non-water animals according to their location. Therefore the correct answer is a. Amy: wildlife in or near water = turtles, crayfish, goldfish non-water wildlife = fox, deer, bobcat.

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In the reaction fecl2 + 2naoh fe(oh)2(s) + 2nacl, if 6 moles of fecl2 are added to 6 moles of naoh, how many moles of fecl2 would be used up in the reaction?

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Answer:

The coefficient of CO₂ is 5.

Explanation:

    Balancing the reaction:

___C₅H₁₂ + ___O₂ → ___CO₂ + ___H₂O

There are 5 C in the left side, so we put 5 on the right side:

___C₅H₁₂ + ___O₂ →  5CO₂ + ___H₂O

There are 12 H in the left side, so we put 6 as the coefficient of H₂O:

___C₅H₁₂ + ___O₂ →  5CO₂ + 6H₂O

Finally, there are 16 O in the right side, so we put 8 as the coefficient of O₂

___C₅H₁₂ + 8O₂ →  5CO₂ + 6H₂O

The coefficient of CO₂ is 5.

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The sum of the numerator and denominator of a fraction expressed in simplest form is 17. if 3 is added to the numerator, the value of the fraction will be 1. what is the fraction?

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The basis to respond this question are:

1) Perpedicular lines form a 90° angle between them.

2) The product of the slopes of two any perpendicular lines is – 1.

So, from that basic knowledge you can analyze each option:

a.Lines s and t have slopes that are opposite reciprocals.

TRUE. Tha comes the number 2 basic condition for the perpendicular lines.

slope_1 * slope_2 = – 1 => slope_1 = – 1 / slope_2, which is what opposite reciprocals means.

b.Lines s and t have the same slope.

FALSE. We have already stated the the slopes are opposite reciprocals.

c.The product of the slopes of s and t is equal to -1

TRUE: that is one of the basic statements that you need to know and handle.

d.The lines have the same steepness.

FALSE: the slope is a measure of steepness, so they have different steepness.

e.The lines have different y intercepts.

FALSE: the y intercepts may be equal or different. For example y = x + 2 and y = -x + 2 are perpendicular and both have the same y intercept, 2.

f.The lines never intersect.

FALSE: perpendicular lines always intersept (in a 90° angle).

g.The intersection of s and t forms right angle.

TRUE: right angle = 90°.

h.If the slope of s is 6, the slope of t is -6

FALSE. – 6 is not the opposite reciprocal of 6. The opposite reciprocal of 6 is – 1/6.

So, the right choices are a, c and g.

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A pharmacy technician added 10 ml of a 20% (w/v) solution of potassium chloride to a 500 ml bag of normal saline. what is the percentage strength of potassium chloride in the bag? round to the nearest hundreth. do not enter the percentage sign in your answer; enter only the number

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This problem is to apply Roult’s Law.

Roult’s Law states that the vapor pressure, p, of a solution of a non-volatile solute is equal to the vapor pressure of the pure solvent, Po solv, times the mole fraction of the solvent, Xsolv

p = Xsolv * Po sol

X solv = number of moles of solvent / number of moles of solution

The solvent is water and the solute (not volatile) is glycerin.

Number of moles = mass in grams / molar mass

mass of water = 132 ml * 1 g/ml = 132 g

molar mass of water = 18 g/mol

=> number of moles of water = 132 g / 18 g/mol = 7.33333 mol

mass of glycerin = 27.2 g

molar mass of glycerin:, C3H8O3: 3 * 12 g/mol + 8 * 1 g/mol + 3*16 g/mol = 92 g/mol

number of moles of glycerin = 27.2g / 92 g/mol = 0.29565

total number of moles = 7.33333 moles + 0.29565 moles = 7.62898 moles

=> X solv = 7.33333 / 7.62898 = 0.96125

=> p = 0.96125 * 31.8 torr ≈ 30.57 torr ≈ 30.6 torr.

Answer: 30.6 torr

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Instructions:Select the correct answer. Why does a solid change to liquid when heat is added? A-The spacing between particles decreases. B-Particles lose energy. C-The spacing between particles increases. D-The temperature decreases.

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There are two systems in the human body that are responsible for the coordination between the functions of different systems to achieve the unity of the living organism’s body. These two systems are the nervous system and the endocrine system. The action of the nervous system is fast and takes a short time, while the action of the endocrine system is slow and takes a long time.

The functional unit of the nervous system is the nerve cell or the neuron. The neuron consists of a cell body and the axon. The cell body starts with the dendrites that receive the messages or the impulses from other neurons or from different sense organs or receptors. These impulses are then transmitted through the cell body. The cell body contains a nucleus and different organelles which help the nerve cell to perform its functions. The nerve impulse is then transmitted to the axon.

The axon is an extension from the cell body. There are some cells called Schwan cells that secrete a myelin sheath to insulate the axon from the surrounding medium. The insulated axons have more ability to conduct the impulses than non-insulated axons. The axon ends with the terminal arborizations. The terminal arborizations of a nerve cell connect to the dendrites of the next cell or to the afferent organ. The gaps between the dendrites and the terminal arborizations are called the synapses.

The nerve impulse is an electrochemical phenomenon i.e. an electrical phenomenon with a chemical nature. The membrane of the axon acts as a barrier between an outside positively charged medium and an inside negatively charged medium. This makes a potential difference of  -70mV. This state is called the resting potential. When the membrane is subjected to a stimulus, the positive charges enter to inside and the negative charges exit to the outside. The potential difference now becomes +40mV. This state is called the depolarization state. The point of stimulation acts as a new stimulus for the next point and so on. The membrane sooner gains its permeability again and the positive charges return to the outside and the negative charges to inside. This state is called repolarization.

The nerve impulse reaches the synapse. There are some neurotransmitters that are excited by the nerve impulse coming and carry the message across the membrane. Some receptors receive theses neurotransmitters on the dendrites of the next neuron. These receptors act as a stimulus for the new cell.

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Which of the following numbers must be added to complete the square in the equation below? x²+18x= -27 A. 18 B. 9 C. 54 D. 81

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Answer:  The correct option is (C). 10 = square root of the quantity of x minus 8 all squared plus y minus 9 all squared

Step-by-step explanation:  Given that the segment AB has point A located at (8, 9). The distance from A to B is 10 units.

We are to select the correct option that could be used to calculate the coordinates for point B.

Let, (x, y) be the co-ordinates of point B.

According to distance formula, the distance between two points (a, b) and (c, d) is given by

d=sqrt{(c-a)^2+(d-b)^2}.

Therefore, the distance between the points A(8, 9) and B(x, y) is given by

d=sqrt{(x-8)^2+(y-9)^2}.

Since, distance between A and B is 10 units, so

d = 10.

Therefore,

10=sqrt{(x-8)^2+(y-9)^2}.

Thus, the correct statement is

10 = square root of the quantity of x minus 8 all squared plus y minus 9 all squared.

Option (C) is correct.

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An automobile’s radiator has a capacity of fifteen quarts, and it currently contains twelve quarts of a thirty percent antifreeze solution. How many quarts of pure antifreeze must be added to strengthen the solution to forty percent? 2 quarts 3 quarts 4 quarts

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Answer:

Option C – BD=76 cm

Step-by-step explanation:

Given : You are designing a diamond-shaped kite. you know that AD = 44.8 cm, DC = 72 cm, and AC = 84.8 cm.

To find : How long BD should it be?

Solution :

First we draw a rough diagram.

The given sides were AD = 44.8 cm, DC = 72 cm and AC = 84.8 cm.

According to properties of kite

Two disjoint pairs of consecutive sides are congruent.

So, AD=AB=44.8 cm

DC=BC=72 cm

The diagonals are perpendicular.

So, AC ⊥ BD

Let O be the point where diagonal intersect let let the partition be x and y.

AC= AO+OC

AC=  x+y=84.8 …….[1]

Perpendicular bisect the diagonal BD into equal parts let it be z.

BD=BO+OD

BD=z+z

Applying Pythagorean theorem in ΔAOD

where H=AD=44.8 ,P= AO=x , B=OD=z

H^2=P^2+B^2

(44.8)^2=x^2+z^2  ………[2]

Applying Pythagorean theorem in ΔCOD

where H=DC=72 ,P= OC=y , B=OD=z

H^2=P^2+B^2

(72)^2=y^2+z^2 …………[3]

Subtract [2] and [3]

(72)^2-(44.8)^2=y^2+z^2-x^2-z^2

5184-2007.04=(x+y)(x-y)

3176.96=(84.8)(x-y)

37.464=x-y ……….[4]

Add equation [1] and [4], to get values of x and y

x+y+x-y=84.8+37.464

2x=122.264

x=61.132

Substitute x in [1]

x+y=84.8

61.132+y=84.8

y=23.668

Substitute value of x in equation [2], to get z

(44.8)^2=x^2+z^2

(44.8)^2=(23.668)^2+z^2

2007.04-560.174224=z^2

z=sqrt{1446.865776}

z=38.06

We know, BD=z+z

BD= 38.06+38.06

BD= 76.12

Nearest to whole number BD=76 cm

Therefore, Option c – BD=76 cm is correct.

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What is the total amount in an account that has had $35 per month added into it for 30 years and grew with an annual interest rate of 7%?

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You need to determine the number of ways in which 30 competitors from 50 can qualify. First, you have to realize that the order is irrelevant, that is: it is the same competitor_1, competitor _2, competitor _3 than competitor_3, competitor_2, competitor_1, or any combination of those three competitors.

So, the number of ways is which 30 competitors from 50 can qualify is given by the formula of combinations, which is:

C (m,n) = m! / (n! * (m -n)! )

=> C (50,30) = 50! / (30! (50 – 30)! ) = (50!) / [30! (50 – 30)!] = 50! / [30! 20!] =

 = 47,129,212,243,960 different ways the qualifiying round of 30 competitors can be selected from the 50 competitors.

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Which number produces an irrational number when added to 0.5 a. 0.555… b. square root of 3 c 1/3 d. square root of 16

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Answer:  The correct option is (C). 10 = square root of the quantity of x minus 8 all squared plus y minus 9 all squared

Step-by-step explanation:  Given that the segment AB has point A located at (8, 9). The distance from A to B is 10 units.

We are to select the correct option that could be used to calculate the coordinates for point B.

Let, (x, y) be the co-ordinates of point B.

According to distance formula, the distance between two points (a, b) and (c, d) is given by

d=sqrt{(c-a)^2+(d-b)^2}.

Therefore, the distance between the points A(8, 9) and B(x, y) is given by

d=sqrt{(x-8)^2+(y-9)^2}.

Since, distance between A and B is 10 units, so

d = 10.

Therefore,

10=sqrt{(x-8)^2+(y-9)^2}.

Thus, the correct statement is

10 = square root of the quantity of x minus 8 all squared plus y minus 9 all squared.

Option (C) is correct.

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10g of an unknown compound are added to water to form a 7.89 molar solution. if 2 liters of solution are present, what is the molar mass of the unknown compound?

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This problem is to apply Roult’s Law.

Roult’s Law states that the vapor pressure, p, of a solution of a non-volatile solute is equal to the vapor pressure of the pure solvent, Po solv, times the mole fraction of the solvent, Xsolv

p = Xsolv * Po sol

X solv = number of moles of solvent / number of moles of solution

The solvent is water and the solute (not volatile) is glycerin.

Number of moles = mass in grams / molar mass

mass of water = 132 ml * 1 g/ml = 132 g

molar mass of water = 18 g/mol

=> number of moles of water = 132 g / 18 g/mol = 7.33333 mol

mass of glycerin = 27.2 g

molar mass of glycerin:, C3H8O3: 3 * 12 g/mol + 8 * 1 g/mol + 3*16 g/mol = 92 g/mol

number of moles of glycerin = 27.2g / 92 g/mol = 0.29565

total number of moles = 7.33333 moles + 0.29565 moles = 7.62898 moles

=> X solv = 7.33333 / 7.62898 = 0.96125

=> p = 0.96125 * 31.8 torr ≈ 30.57 torr ≈ 30.6 torr.

Answer: 30.6 torr

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[06.01]the same amount of heat is added to 100 g of water and 1 kg of water starting at the same temperature. what will happen?

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The equation for how temperature changes the resistance R is: 

R=R₀(1+α(T-T₀)), where R₀ is the resistance at T₀=20°C, T is the temperature for which we want to calculate the resistance and α is the temperature coefficient for resistance. 

The resistance of the copper wire increases by 18% or by 0.18, so the new value for the resistance is R=1.18*R₀.

T₀=20°C
=0.0068
R=1.18*R₀

Now we need to input that into the equation for resistance change and solve for temperature T.  

1.18R₀=R₀(1+α(T-20)), R₀ cancels out,

1.18=1+α(T-20),

1.18-1=α(T-20), we divide by α,

0.18/α=T-20, we put 20 on the left side,

26.47+20=T

T=46.47°C

So the temperature on which the resistance of copper wire will increase by 18% is T=46.47°C. 

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If nickel is added to copper sulfate solution, the nickel will replace the copper. write the balanced equation

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Explanation :

In the net ionic equations, we are not include the spectator ions in the equations.

Spectator ions : The ions present on reactant and product side which do not participate in a reactions. The same ions present on both the sides.

(a) The given balanced ionic equation is,

Ni(NO_3)_2(aq)+Na_2S(aq)rightarrow NiS(s)+2NaNO_3(aq)

The ionic equation in separated aqueous solution will be,

Ni^{2+}(aq)+2NO_3^-(aq)+2Na^+(aq)+S^{2-}(aq)rightarrow NiS(s)+2Na^+(aq)+2NO_3^-(aq)

In this equation, Na^+text{ and }NO_3^- are the spectator ions.

By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.

The net ionic equation will be,

Ni^{2+}(aq)+S^{2-}(aq)rightarrow NiS(s)

(b) The given balanced ionic equation is,

NaNO_3(aq)+KBr(aq)rightarrow KNO_3(s)+NaBr(aq)

The ionic equation in separated aqueous solution will be,

Na^+(aq)+NO_3^-(aq)+K^+(aq)+Br^-(aq)rightarrow KNO_3(s)+Na^+(aq)+Br^-(aq)

In this equation, Na^+text{ and }Br^- are the spectator ions.

By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.

The net ionic equation will be,

NO_3^-(aq)+K^+(aq)rightarrow KNO_3(s)

(c) The given balanced ionic equation is,

Li_2SO_4(aq)+BaCl_2(aq)rightarrow BaSO_4(s)+2LiCl(aq)

The ionic equation in separated aqueous solution will be,

2Li^+(aq)+SO_4^{2-}(aq)+Ba^{2+}(aq)+2Cl^-(aq)rightarrow BaSO_4(s)+2Li^+(aq)+2Cl^-(aq)

In this equation, Li^+text{ and }Cl^- are the spectator ions.

By removing the spectator ions from the balanced ionic equation, we get the net ionic equation.

The net ionic equation will be,

SO_4^{2-}(aq)+Ba^{2+}(aq)rightarrow BaSO_4(s)

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