One way to increase the rate of a reaction occurring in solution is to stir the solution. how does this increase the rate of the reaction? a. it increases the number of collisions between molecules. b. it increases the number of reactants in the solution. c. it increases the temperature of the solution. d. it increases the pressure of the reactants.

Calcium hydride (cah2) reacts with water to form hydrogen gas: cah2(s) + 2h2o(l) → ca(oh)2(aq) + 2h2(g) how many grams of cah2 are needed to generate 45.0 l of h2 gas at a pressure of 0.995 atm and a temperature of 32 °c?

Which compounds have the empirical formula ch2o? a. c2h4o2 b. c3h6o3 c. ch2o2 d. c5h10o5 e. c6h12o6

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)