1. When heated, calcium carbonate gives off CO2 according to thefollowing reaction: CaCO3(s) → CO2(g) + CaO(s) You perform thisreaction in lab by heating a test tube containing CaCO3 and collectthe CO2 over water for later analysis. You collect 20.3 mL of gas.What mass of CO2 have you collected? Assume the temperature andpressure of your lab is 25 °C and 1.00 atm. The vapor pressure ofwater at 25 °C is 24.0 Torr. (a) 35.4 mg (b) 36.5 mg (c) 611 mg (d)877 mg (e) 26.9 g
2. At 25 °C, the Ksp of CaSO4 is 9.1×10–6 . How many of thefollowing procedures will change the value of Ksp for CaSO4? I.presence of Na2SO4 in solution II. changing the temperature of thesolution III. changing the amount of water in solution IV. presenceof Ca(NO3)2 in solution (a) 0 (b) 1 (c) 2 (d) 3 (e) 4
