The two most abundant elements in the universe are:
a. hydrogen and oxygen
c. hydrogen and helium
b. oxygen and nitrogen
d. carbon and oxygen

An alkaline battery produces electrical energy according to the following equation. zn(s) + 2 mno2(s) + h2o(l) zn(oh)2(s) + mn2o3(s) (a) determine the limiting reactant if 17.5 g zn and 31.0 g mno2 are used. (type your answer using the format ch4 for ch4.) (b) determine the mass of zn(oh)2 produced. _ g

Balance the following reaction. as2s3 + 9o2 → 2as2o3 + so2

In an exothermic reaction at equilibrium, what is the effect of lowering the temperature? a. the reaction makes more products. b. the reaction makes more reactants. c. the reaction is unchanged.