Name
Date
Pd
Molar Concentration
Part A: Describing Molar Concentration
1.
Sodium chloride was dissolved in water to produce a 1.5 M solution. Use words to describe what this
concentration tells us about the NaCl solution.
2.
A 45.3 g sample of potassium nitrate (KNO3) is dissolved in enough water to make 225 mL of solution.
Determine the molar concentration of the potassium nitrate.
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Factor label (convert mL to L):
Calculate the molar concentration of KNO3, [KNO3]. Show your work.
3.
Find the molarity of a solution made from 275 g of CuSO4 dissolved in enough water to make 4.25 L.
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Calculate the molar concentration of CuSO4, [CuSO4]. Show your work.
4.
An alcoholic iodine solution (“tincture” of iodine) is prepared by dissolving 5.15 g of iodine crystals in
enough alcohol to make a volume of 225 mL. Calculate the molarity of iodine in the solution. (Be careful
with the chemical formula for iodine. It is a diatomic element.)
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Calculate the molar concentration. Show your work.
5.
What final volume would be needed in order to prepare a 0.25 M NaCl solution from 5.2 g of NaCl (s)?
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Calculate the volume. Show your work and how you rearrange the molarity equation.
6.
How many grams of silver nitrate are needed to prepare 250 mL of 0.100 M silver nitrate (AgNO 3)
solution?
Calculate the moles of AgNO3. Show your work and how you rearrange the molarity equation.
Molar mass equality: ________________ = __________________
Factor label (convert moles to grams):
7.
If 10.0 g of AgNO3 is available, find the volume needed to prepare a 0.25 M AgNO3 solution.
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Calculate the volume. Show your work and how you rearrange the molarity equation.
8.
Concentrated hydrochloric acid is made by pumping hydrogen chloride gas into distilled water. If
concentrated HCl contains 439 g of HCl per liter, what is the molarity?
Molar mass equality: ________________ = __________________
Factor label (convert grams to moles):
Calculate the molar concentration. Show your work.
Answers: 2) 1.99 M; 3) 0.405 M; 4) 0.902 M;
5) 360 mL; 6) 4.25 g; 7) 0.235 L; 8) 12.0 M