1) in a chemical equation

a) the mass of the reactants equals the mass of the products

b)the mass of the products is greater than the mass of reactants

c)the number of atoms in the reactants and products must change

d)energy as heat must be added to the reactants

2)a chemical equation is balanced when the

a)coefficients of the reactants equal the coefficients of the products

b)same number of each kind of atom appears in the reactants and in the products

c)products and reactants are the same chemicals

d)subscripts of the reactants equal the subscripts of the products

3) Which equation is NOT balanced?

a)2H2 + O2 --> 2H2O

b)4H2 + 2O2 --> 4H20

c)H2 + H2 + O2 --> H2O + H2O

d)2h2 + O2 --> H20

4)tell what type of chemical equation is represented by the following formula equation. Then balance the equations

C3H8(g) + O2(g) ---> (heat is applied) CO2(g) + H2O (l)