Chemistry Solubility and Vapor Pressure

What mass of solid that has a molar mass 89.0 g/mol should be added to 100.0 g of benzene to raise the boiling point of benzene by 2.42°C? (The boiling point elevation constant of benzene is 2.53°C•kg/mol.)

• 2.84 g

• 8.52 g

• 21.5 g

• 93.0 g

What is the relationship between the concentration of particles in a solution and the solution’s vapor pressure?

• As solute concentration increases, vapor pressure increases.

• As solute concentration increases, vapor pressure decreases.

• As the concentration of electrolytes increases, vapor pressure increases. However, as the concentration of nonelectrolytes increases, vapor pressure decreases.

• As the concentration of electrolytes increases, vapor pressure decreases. However, as the concentration of nonelectrolytes increases, vapor pressure increases.

What mass of solid that has a molar mass of 46.0 g/mol should be added to 150.0 g of benzene to raise the boiling point of benzene by 6.28°C? (The boiling point elevation constant of benzene is 2.53°C•kg/mol.)

• 2.48 g

• 8.25 g

• 17.1 g

• 43.3 g

Which solute, an electrolyte or a nonelectrolyte, has the greater effect on the boiling point when a given amount of each solute is dissolved in the same mass of water?

• The nonelectrolyte does because it disperses into molecules.

• The electrolyte does because it disperses into molecules.

• The nonelectrolyte does because it dissociates into ions.

• The electrolyte does because it dissociates into ions.

What is the molality of a solution that is obtained by dissolving 2.922 g of NaCl into 1000.0 g of water if the molar mass of NaCl is 58.44 g/mol?

• 0.05000 m

• 2.922 m

• 5.856 m

• 20.00 m

A government laboratory wants to determine whether water in a certain city has any traces of fluoride and whether the concentration exceeds the recommended 4.00 ppm. A 5.00-g sample of this water is found to have 0.152 mg of fluoride. Should the water be declared safe for drinking?

• 3.04 ppm < 4.00 ppm, safe to drink

• 7.60 ppm > 4 ppm, safe to drink

• 30.4 ppm > 4 ppm, unsafe to drink

• 30,400 ppm > 4 ppm, unsafe to drink

Tags

NGSS.HS-ESS2-5

A 250-mL aqueous solution contains 1.56 10^–5 g of methanol and has a density of 1.03 g/mL. What is the concentration in ppm?

• 6.1 10^-8 ppm

• 1.5 10^-5 ppm

• 0.061 ppm

• 15 ppm

The molality of a solution that is made by dissolving a certain mass of ethanol in 85.4 g of water is 0.950 m. How many moles of ethanol were dissolved?

• 0.0811 mol

• 0.0899 mol

• 11.1 mol

• 81.1 mol

In a coffee shop, the following coffee samples are prepared for customers.

i. 10 g of sugar added to 100 g of coffee

ii. 10 g of sugar added to 200 g of coffee

iii. 4 g of sugar added to 200 g of coffee

iv. 4 g of sugar added to 100 g of coffee

Based on the amount of sugar added, which sequence ranks the coffee from the sweetest coffee to the least-sweet coffee?

• i, ii , iii, iv

• iii, iv, ii, i

• iv, i, ii, iii

• i, ii, iv, iii

A number of beakers have different concentrations of a solution. Which statement best describes the most concentrated solution?

• It has the largest volume.

• It has the most solute for a given volume.

• It has the greatest amount of solute.

• It has the most volume for a given amount of solute.

Tags

NGSS.HS-PS1-5