IGCSE – HONORS – SOLUTIONS STUDY GUIDE
COPY THE FOLLOWING QUESTIONS AND ANSWER. HIGHLIGHT THE QUESTIONS AND BOX THE ANSWER
1: Sea water contains roughly 28.0 g of NaCl per liter. What is the molarity? ANS: 0.479
2: What is the molarity of 245.0 g of H2SO4 dissolved in 1.000 L of solution? ANS: 2.498
3: What is the molarity of 5.30 g of Na2CO3 dissolved in 400.0 mL solution? ANS: 0.125
4: What is the molarity of 5.00 g of NaOH in 750.0 mL of solution? ANS: 0.167
5: How many moles of Na2CO3 are there in 10.0 L of 2.00 M solution? ANS: 20.0
6: How many moles of Na2CO3 are in 10.0 mL of a 2.0 M solution? ANS: 0.020
7: How many moles of NaCl are contained in 100.0 mL of a 0.200 M solution? ANS: 0.0200
8: What weight (in grams) of NaCl would be contained in problem #7? ANS: 1.17
9: What weight (in grams) of H2SO4 would be needed to make 750.0 mL of 2.00 M solution? ANS: 147
10: What volume (in mL) of 18.0 M H2SO4 is needed to contain 2.45 g H2SO4? ANS: 1.39
11: What volume (in mL) of 12.0 M HCl is needed to contain 3.00 moles of HCl? ANS: 250
12: How many grams of Ca(OH)2 are needed to make 100.0 mL of 0.250 M solution? ANS: 1.85
13: What is the molarity of a solution made by dissolving 20.0 g of H3PO4 in 50.0 mL of solution? ANS: 4.08
14: What weight (in grams) of KCl is there in 2.50 liters of 0.500 M KCl solution? ANS: 93.2
15: What is the molarity of a solution containing 12.0 g of NaOH in 250.0 mL of solution? ANS: 1.20
16: Determine the molarity of these solutions:
a) 4.67 moles of Li2SO3 dissolved to make 2.04 liters of solution. ANS: 2.29
b) 0.629 moles of Al2O3 to make 1.500 liters of solution. ANS: 0.419
c) 4.783 grams of Na2CO3 to make 10.00 liters of solution. ANS: 0.045
d) 0.897 grams of (NH4)2CO3 to make 250 mL of solution. ANS: 9.33 x10^-3
e) 0.0348 grams of PbCl2 to form 45.0 mL of solution. ANS: 1.25 x10^-4
17: Determine the number of moles of solute to prepare these solutions:
a) 2.35 liters of a 2.00 M Cu(NO3)2 solution. ANS: 4.70
b) 16.00 mL of a 0.415-molar Pb(NO3)2 solution. ANS: 6.64 x10^-3
c) 3.00 L of a 0.500 M MgCO3 solution. ANS: 1.50
d) 6.20 L of a 3.76-molar Na2O solution. ANS: 23.32
18: Determine the grams of solute to prepare these solutions:
a) 0.289 liters of a 0.00300 M Cu(NO3)2 solution. ANS: 0.162
b) 16.00 milliliters of a 5.90-molar Pb(NO3)2 solution. ANS: 31.25
c) 508 mL of a 2.75-molar NaF solution. ANS: 58.674
d) 6.20 L of a 3.76-molar Na2O solution. ANS: 1445.34
e) 0.500 L of a 1.00 M KCl solution. ANS:37.25
f) 4.35 L of a 3.50 M CaCl2 solution. ANS: 1689.975
19: Determine the final volume of these solutions:
a) 4.67 moles of Li2SO3 dissolved to make a 3.89 M solution. ANS: 1.20L
b) 4.907 moles of Al2O3 to make a 0.500 M solution. ANS: 9.814L
c) 0.783 grams of Na2CO3 to make a 0.348 M solution. ANS:0.02123 L or 21.23 mL
d) 8.97 grams of (NH4)2CO3 to make a 0.250-molar solution. ANS: 0.373L
e) 48.00 grams of PbCl2 to form a 5.0-molar solution. ANS:0.0345
20: A solution of calcium bromide contains 20.0 g dm-3. What is the molarity of the solution. ANS:0.1
CHALLENGE QUESTIONS – THESE QUESTIONS ARE REQUIRED IF YOU WANT EXTRA CREDIT IN YOUR TEST
YOU MUST SHOW YOUR COMPLETE WORK TO GET THE CREDIT
21:A student placed 11.0 g of glucose (C6H12O6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100. mL mark on the neck of the flask was reached. The flask was then shaken until the solution was uniform. A 20.0 mL sample of this glucose solution was diluted to 0.500L. How many grams of glucose are in 100. mL of the final solution?
22: Commercial bleach solution contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Caculate the molarity of this solution. (Hints: assume you have 1.00 L of solution; molar mass of NaClO 74.4 g/mol)
23: What is the molality (and molarity) of a 20.0% by mass hydrochloric acid solution? The density of the solution is 1.0980 g/mL.
24: 25.0 mL of 0.250 M KI, 25.0 mL of 0.100 K2SO4, and 15.0 mL of 0.100 M MgCl2 were mixed together in a beaker. What are the molar concentrations of I¯, Cl¯ and K+ in the beaker?
25:Calculate the total concentration of all the ions in each of the following solutions:
a. 3.25 M NaCl
b. 1.75 M Ca(BrO3)2
c. 12.1 g of (NH4)2SO3 in 615 mL in solution.