Question

Please help me

What is missing from the equation, and how do you know?

A
Three grams of H2S because the mass of the products must equal the mass of the reactants.
B
213 grams of H2S because the mass of the products must be four times the mass of the reactants.
C
143 grams of H2S because the mass of the products must be three times the mass of the reactants.
D
73 grams of H2S because the mass of the products must be double the mass of the reactants.

Answer 1

The answer is A, because 55+15=70, and 70-67=3