Unit 11 BR #4: Percent Composition and Dilution

Front

What is an electrolyte?

Back

An electrolyte is a substance that dissociates into ions when dissolved in water, allowing the solution to conduct electricity. Example: Sodium chloride (NaCl) is an electrolyte.

Front

How do you calculate percent composition by mass?

Back

Percent composition by mass = (mass of solute / total mass of solution) x 100%.

Front

What is the percent composition by mass of a solution prepared by dissolving 8.10 g of hydrogen chloride in 150.7 g of H2O?

Back

5.1%

Front

What is the percent composition by mass of a solution prepared by dissolving 1.29 g of calcium sulfite in 730 g of H2O?

Back

0.17%

Front

What is the percent composition by mass of a solution prepared by dissolving 193.6 g of magnesium chlorite in 917 g of H2O?

Back

17%

Front

What remains constant during a dilution?

Back

The total moles of solute remain constant during a dilution.

Front

What is the formula for calculating the concentration of a solution?

Back

Concentration (C) = moles of solute / volume of solution (L).

Front

What is the difference between molarity and percent by mass?

Back

Molarity is the number of moles of solute per liter of solution, while percent by mass is the mass of solute divided by the total mass of the solution, expressed as a percentage.

Front

What is the role of water in a solution?

Back

Water acts as a solvent, dissolving solutes to form a solution.

Front

What is a concentrated solution?

Back

A concentrated solution contains a large amount of solute relative to the amount of solvent.