What is not true for a catalyst? 1. a catalyst increases the rate of a chemical reaction by decreasing activation energy. 2. a catalyst is not consumed in chemical reactions. 3. a catalyst can convert an endothermic reaction into an exothermic reaction. 4. a catalyst may be used in the solid, liquid or gaseous phase.

3. A catalyst can convert an endothermic reaction into an exothermic reaction.

Explanation:

What is NOT true for a catalyst?

1. A catalyst increases the rate of a chemical reaction by decreasing activation energy. TRUE. A positive catalyst increases the reaction rate by decreasing the activation energy.

2. A catalyst is not consumed in chemical reactions. TRUE. A catalyst is recovered unaltered at the end of the reaction.

3. A catalyst can convert an endothermic reaction into an exothermic reaction. FALSE. A catalyst cannot modify the enthalpy of a reaction.

4. A catalyst may be used in the solid, liquid or gaseous phase. TRUE. If the catalyst is in the same phase as the reaction, the catalysis is homogeneous. Else, the catalysis is heterogeneous.

a. the law of proportion states the combination of 2 atoms in a specific ratio to produce multiple compounds such as the given statement of question ‘1st compound contains 88.8 % cu ’ indicates 88.8 g of cu is present along with 11.2 g oxygen in 100 g of compound whereas the statement ‘2st compound contains 79.9 % cu ’ indicates 79.9 g of cu is present along with 20.1 g oxygen in 100 g of compound

1st compound contains 88.8 g cu

for cu

m = 63 g /mol

atomic % = 88.8 /63 = 1.42

for o

m = 16 g /mol

atomic % = 11.2 /16 = 0.7

b. the emperical formula of 1st compound is

cu1.4o0.7

cu2o