4NH3(g) + 5O2(g) -> 4NO(g) + 6H2O(g) How many moles of ammonia (NH3) are needed if 2.75 moles of water (H2O) were produced?

4.13 mol

1.83 mol

4 mol

(only respond if you have the answer)

6.8 mol

Which statement is true about a catalyst? a: a catalyst decreases the rate of the reaction. b. a catalyst is consumed during a chemical reaction. c. a catalyst lowers the activation energy of a reaction. d. a catalyst increases the reactant concentration during a reaction.