Unit 08 Post-Assessment Remediation (PAR)

Which statement describes a solution of sodium chloride in water?

• The mixture is heterogeneous, the solute is NaCl and the solvent is H₂O.

• The mixture is heterogeneous, the solute is H₂O and the solvent is NaCl.

• The mixture is homogeneous, the solute is NaCl and the solvent is H₂O.

• The mixture is homogeneous, the solute is H₂O and the solvent is NaCl.

A solution contains 25 grams of KNO₃ dissolved in 200 grams of H₂O. Which numerical setup can be used to calculate the percent by mass of KNO₃ in this solution?

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Based on Table G, what is the approximate mass of NH₃ that must be dissolved in 200 grams of water to produce a saturated solution at 20°C?

• 28 g

• 56 g

• 100 g

• 112 g

What is the total mass of solute in 1000 grams of a solution having a concentration of 5 parts per million?

• 0.005 g

• 0.05 g

• 0.5 g

• 5 g

Which solution is saturated?

• 1

• 2

• 3

• 4

Base your answer to the question on the information below.

Two alcohols that are used in our everyday lives are rubbing alcohol and ethylene glycol. Rubbing alcohol is used as an antiseptic. Ethylene glycol is the main ingredient in antifreeze, which is used in automobile cooling systems.

Which of the following is a correct numerical setup for calculating the total number of moles of ethylene glycol needed to prepare 2.50 liters of a 10.0 M solution?

• 10.0 M = x mol / 2.50 L

• x mol = 10.0M / 2.50 L

• 10.0 L = x mol / 2.50M

According to Reference Table G, which solution at equilibrium contains 50 grams of solute per 100 grams of H₂O at 75°C?

• an unsaturated solution of KCl

• an unsaturated solution of KClO₃

• a saturated solution of KCl

• a saturated solution of KClO₃

What is the total number of grams of NaI(s) needed to make 1.0 liter of a 0.010 M solution?

• 0.015

• 0.15

• 1.5

• 15

Which solution is the most concentrated?

• 1 mole of solute dissolved in 1 liter of solution

• 2 moles of solute dissolved in 3 liters of solution

• 6 moles of solute dissolved in 4 liters of solution

• 4 moles of solute dissolved in 8 liters of solution

Based on Reference Table F, which solution will contain the highest concentration of iodide ions?

• lead iodide

• silver iodide

• mercury (II) iodide

• iron (II) iodide