Q: A solution containing 22.5 mg of an unknown protein per 25.0 mL solution has an osmotic pressure of 2.18 torr at $$25^\circ\mathrm{C}. $$What is the molar mass of the protein? ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$}$$, $$1\ \mathrm{atm} = 760\ \mathrm{torr})$$

$$7.64 \times 10^3$\ \mathrm{g/mol}$$

Question 1

Which of the following molecules exhibits the strongest dipole-dipole intermolecular forces?

Accepted Answer

$$\mathrm{SO_2$}$$

Question 2

A solution contains 20 g of $$\mathrm{$$KNO_3$$}$$ per 100 g of water at $$40^\circ\mathrm{C}. $$According to the solubility chart, is the solution unsaturated, saturated, or supersaturated?

Accepted Answer

Unsaturated

Question 3

A solution containing 22.5 mg of an unknown protein per 25.0 mL solution has an osmotic pressure of 2.18 torr at $$25^\circ\mathrm{C}. $$What is the molar mass of the protein? ($$R = 0.0821\ \mathrm{L\cdot atm\cdot $$mol^{-1}$$\cdot K$$^{-1}$$}$$, $$1\ \mathrm{atm} = 760\ \mathrm{torr})$$

Accepted Answer

$$7.64 	imes 10^3$\ \mathrm{g/mol}$$

Question 4

Which process is best described as deposition?

Accepted Answer

A gas becomes a solid.

Question 5

Which intermolecular forces are present in $$\mathrm{CH_3CH_2OH}$$?

Accepted Answer

Dispersion, hydrogen bonding, and dipole-dipole forces are present.

Question 6

What is the strongest type of intermolecular force present in $$\mathrm{CH_3CH_2NH_2}$$?

Accepted Answer

Hydrogen bonding

Question 7

Which one of the following has a definite shape and volume?

Accepted Answer

A solid

Question 8

What is the molarity of a solution prepared by dissolving 200 g of $$\mathrm{NH_4Cl} in $$enough water to make 1.00 L of solution? ($$\mathrm{NH_4Cl}$$ molar mass = $$53.50\ \mathrm{g/mol})$$

Accepted Answer

$$3.95\ \mathrm{M}$$

Question 9

A solution is prepared by dissolving 49.3 g of AgI in enough water to form 473 mL of solution. Calculate the mass % of AgI in the solution if the density is $$1.12\ \mathrm{g/mL}.$$

Accepted Answer

$$9.30\%$$

Question 10

To increase the solubility of a gas in a liquid the most, which change should be made?

Accepted Answer

Decrease the temperature and raise the pressure.

Question 11

What is the mole fraction of ethanol in a solution made by dissolving 14.6 g of ethanol ($$\mathrm{C_2H_5OH}) in 53.6 g of $$water?

Accepted Answer

$$0.0962$$

Question 12

A solution is prepared by dissolving 40.0 g of sucrose ($$\mathrm{C$$_{12}$$H_{22}O$$_{11}}$$) in 250 g of water at 25$$^\circ\mathrm{C}$$. What is the vapor pressure of the solution if the vapor pressure of pure water at 25$$^\circ\mathrm{C}$ is 23.8 mm Hg?

Accepted Answer

$$23.56\ \mathrm{mm\ Hg}$$

Question 13

Which molecule would you expect to be most soluble in water?

Accepted Answer

$$\mathrm{CH_3CH_2CH_2OH}$$

Question 14

Which of the following solutions will have the highest boiling point?

Accepted Answer

$$0.100\ \mathrm{m}\ \mathrm{$$MgCl_2$$}$$

Question 15

A solution is prepared by dissolving 0.100 mol of $$\mathrm{C_2H_5OH} in 0.400 kg of $$water. What is the boiling point elevation? ($$K_b = 0.512\ ^\circ\mathrm{C}\cdot\mathrm{kg/mol}$$, boiling point of pure water = $$100^\circ\mathrm{C})$$

Accepted Answer

$$108^\circ\mathrm{C}$$

Question 16

When 2.00 g of $$\mathrm{NH_4Cl} is $$dissolved in 100 g of water, the temperature drops from $$22.0^\circ\mathrm{C} to$$ $$20.8^\circ\mathrm{C}. $$What is the enthalpy change for the dissolution process?

Accepted Answer

$$20.8\ \mathrm{kJ} of $$heat are released.

Question 17

Choose the pair of substances that are most likely to form a homogeneous solution.

Accepted Answer

$$\mathrm{NaCl} ($$ionic) and $$\mathrm{CH_3OH} ($$polar)

Question 18

Determine the solubility of $$\mathrm{CO_2$} in $$soda water at $$25^\circ\mathrm{C} if $$the pressure of $$\mathrm{CO_2$} is 7.0 $$atm. The Henry's law constant for carbon dioxide in water at this temperature is $$3.4 	imes 10$$^{-2}$$\ \mathrm{mol/L\cdot atm}.$$

Accepted Answer

$$0.24\ \mathrm{M}$$

General Chemistry: Solutions, Intermolecular Forces, and Colligative Properties – Study Notes

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