Chemical Concentrations Group quiz
Name: ________ANSWERS___
__________________________
______________________ __________________________
Molarity problems (M= moles/liter of solution)
period: _____
1) Describe (in words) how you could make a 3.0 Molar solution of sodium chloride.
(3 mol/L)(58g/1 mol) = 174 grams of NaCl/L
Weigh out 174 grams of salt (NaCl) into a flask and dilute up to 1000 mL (1 L) of water.
2) What is the molarity of a solution make by dissolving 125 grams of NH4Cl into a
solution of 850 ml of solution?
125 g of NH4Cl x 1 mol of NH4Cl = 2.78 M
.800 L of H20
53 g of NH4Cl
Look at your solubility curve worksheet and calculate how many grams you could
theoretically dissolve at room temperature (22oC)
37 grams of NH4Cl will dissolve in water at room temperature
3) What is the molarity of a solution that consists of 250 grams of C12H22O11 diluted to
a volume of 1.75 liters?
250 grams of C12H22O11 x 1 mol of C12H22O11 = .418 M
1.75 L of H20
342 g of C12H22O11
4) If you want the concentration to be 2.0 M what must be the final volume of a solution
made with .5 moles of AgNO3?
.5 mol of AgNO3 x 1L
= .25 L
2 mol
5) Which solution would have a higher molar concentration 100 grams of table
salt(NaCl) dissolved into a 1000 ml solution or 200 grams of sugar (C12H22O11)
dissolved into a 1000 ml solution?
Salt has a much higher molar concentration.
What is the molarity of the more concentrated solution?
100 g of NaCl x 1mol NaCl = 17.2 M
.1 L
58 g NaCl