End of Chapter Problems

Test your skills on the following problems.

Molarity

Problem: How many milligrams of NaCN are required to prepare 712 mL of 0.250 M NaCN?

4m

Problem: What volume (in μL) of 0.100 M HBr contains 0.170 moles of HBr?

3m

Problem: How many moles of Ca2+ ions are in 0.100 L of a 0.450 M solution of Ca3(PO4)2?

2m

Problem: How many chloride ions are present in 65.5 mL of 0.210 M AlCl3 solution?

a) 4.02 x 1023 chloride ions

b) 5.79 x 1024 chloride ions

c) 2.48 x 1022 chloride ions

d) 8.28 x 1021 chloride ions

e) 1.21 x 1022 chloride ions

3m

Dilution Reactions

Problem: To what final volume would 100 mL of 5.0 M KCl have to be diluted in order to make a solution that is 0.54 M KCl?

6m

Problem: If 880 mL of water is added to 125.0 mL of a 0.770 M HBrO4 solution what is the resulting molarity?

3m

Titration Reactions

Problem: Consider the following balanced redox equation:

H2O + 2 MnO4  + 3 SO32– ----> 2 MnO2 + 3 SO42– + 2 OH 

How many grams of MnO(MW: 86.94 g/mol) are produced when 32.0 mL of 0.615 M MnO4 (MW: 118.90 g/mol) reacts with excess water and sulfite?

3m

Problem: Iron (III) can be oxidized by an acidic K2Cr2O7 solution according to the net ionic equation:

Cr2O72– + 6 Fe2+ + 14 H+ ----->  2 Cr3+ + 6 Fe3+ + 7 H2O

If it takes 35.0 mL of 0.250 M FeCl2 to titrate 50 mL of a solution containing Cr2O72–, what is the molar concentration of Cr2O72–?

4m

Problem: Vinegar is a solution of acetic acid, CH3COOH, dissolved in water. A 5.54 g sample of vinegar was neutralized by 30.10 mL of 0.100 M NaOH. What is the percent by weight of acetic acid in the vinegar?

6m

Problem: What is the molar mass of a 0.350 g sample of a monoprotic acid if it requires 50.0 mL of 0.440 M Ca(OH)2 to completely neutralize it?

6m

Molecular, Total Ionic & Net Ionic Equations

Example: Give the complete ionic equation for the reaction (if any) that occurs when aqueous solutions of sodium sulfide and copper (II) nitrate are mixed.

4m

Example: Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of H2SO4 and KOH are mixed.

4m

Example: Give the net ionic equation for the reaction (if any) that occurs when aqueous solutions of Na2CO3 and HCl are mixed.

4m