1. How many milliliters of 0.250 M HCl needs to react with excess Zn to produce 0.0375 mol H2? 2. How many milliliters of 0.250 M HCl needs to react with excess Zn to produce 2.5 g ZnCl2?

3. If excess Zn is added to 450 mL of 0.250 M HCl, what mass of ZnCl2 can be produced?

1. suppose a reaction mixture, when diluted with water, afforded 300 ml of an aqueous solution of 30 g of the reaction product malononitrile [ch2(cn)2], which is to be isolated by extraction with ether. the solubility of malononitrile in ether at room temperature is 20.0 g/100 ml, and in water is 13.3 g/100 ml. what weight of malononitrile would be recovered by extraction with (a) three 100-ml portions of ether and (b) one 300-ml portion of ether? suggestion: for each extraction, let x equal the weight extracted into the ether layer. in part (a), the concentration in the ether layer is x/100 and in the water layer is (30 x)/300; the ratio of these quantities is equal to k 20/13.3.