HW 2: Unit 10 Molarity and Mass Percent

What is the percent by mass of a solution made by dissolving 20.0 g of NaCl into 180.0 g of water?

• 10.0 %

• 11.1 %

• 80.0 %

• 20.0 %

Answer explanation

20g / (180g+ 20g) x 100 = 10 %

What is the percent concentration of sugar in pink lemonade if 28 g of sugar is added to 209 g of water?

• 14.7 %

• 5.14 %

• 13.4 %

• 8.47 %

• 11.8 %

Answer explanation

28 g / ( 209g + 28g) x 100 = 11.8 %

The ___ is the part of the solution being dissolved

• solute

• solvent

Answer explanation

The solvent ( usually water) dissolves the solute.

What is the percent by mass of a solution made by dissolving 10.0 g of NaCl into 180.0 g of water?

• 5.26 %

• 5.56 %

• 180.0 %

• 20.0 %

Answer explanation

10 g / (10 g + 180 g) x 100 = 5.26 %

What is the percent by mass of a solution containing 56.5 g of salt in 500 g of water?

• 11.3 %

• 5.56%

• 8.85%

• 10.2 %

Answer explanation

56.5g / ( 56.5g + 500g) x 100 = 10.2 %

Something that is soluble

• can be dissolved
• cannot be dissolved

What is the molarity of a 0.5L sample of a solution that contains 60.0 g of sodium hydroxide (NaOH)

• 0.8 M

• 1.5M

• 3.0M

• 6.0M

A student is preparing solutions for a laboratory experiment by dissolving solid solutes in liquid solvents. Which action will increase the rate of solubility

• lowering the temperature of the solvent

• stirring the solute in the solution

• increasing the pressure on the solution

• increasing the particle size of the solute