Problems
1) How would you prepare a 5% NaCl solution by mass?
2) How would you prepare a 5% NaCl mass/volume solution?
3) Determine the solubility of the following compounds, if soluble indicate the ions you’d expect to be present in solution:
A. K2CO3
B. PbSO4
C. Na2S
D. Ca(NO3)2
4) Write the net ionic equation based on the following molecular equations:
A. HBr(aq) + KOH(aq) -> KBr(aq) + H2O(l)
B. CaS(aq) + 2HBr(aq) -> CaBr2 + H2S(g)
Answers
1) weigh out 5 grams of NaCl and dissolve it in 95 grams of water. Mass% = [mass of solute/(mass of solute + mass solvent)]*100
2) weigh out 5 grams of NaCl and dissolve it in a little bit of water, then dilute the solution to 100 mL using a volumetric flask. (mass solute/100 mL)*100
3) A. K+, CO32-
B. insoluble
C. Na+, S2-
D. Ca2+, NO3–
4) A. H+(aq) + OH–(aq) -> H2O(l)
B. 2H+(aq) + S2-(aq) -> H2S(g)