Categories

## 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

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

Categories

## The cell membrane around a cell forms a barrier that protects and regulates the cell. Certain chemicals can pass through the plasma membrane because they have similar chemical properties as the membrane. Which best describes those that can pass through? They are concentrated. They are soluble. They are diluted. They are heated.

The cell membrane around a cell forms a barrier that protects and regulates the cell. Certain chemicals can pass through the plasma membrane because they have similar chemical properties as the membrane. Which best describes those that can pass through? They are concentrated. They are soluble. They are diluted. They are heated.

Categories

## In a solution of salt and water, if the water can’t dissolve anymore salt, the solution is described as which of the following? a. soluble b. supersaturated c. unsaturated d. saturated

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.

Categories

## Which is a property of both alkenes and alkynes? Both are highly water soluble. The pH of these hydrocarbons tends to be very basic. Their boiling points tend to increase with chain length. Their densities are all much higher than that of water.

Hey there!

In order to solve for the percentage of water in the compound, you will first need to find its total molar mass. You can do this by adding up the molar masses of each individual element in the compound. Then, you will divide the mass that you find of the water molecules by the total mass to get the percentage.

→ Na₂CO₃ × 10 HO

→ Na₂ = 22.9898 × 2 = 45.9796
→ C = 12.0107
→ O₃ = 15.999 × 3 = 47.997
→ 10 H₂O = 18.015 × 10 = 180.15

Now, just add all of those numbers up for the total molar mass.

→ 45.9796 + 12.0107 + 47.997 + 180.15 = 286.1373

The last step is to divide the molar mass of the 10 water molecules by the total mass.

→ 180.15 ÷ 286.1373 = 0.62959 ≈ 0.63