If 9.3 grams of calcium (Ca) and 5.5 grams of sulfur (S) are created, _________ grams of CaS were decomposed. Please fill in the NUMBER only in the box below.

Question

If 9.3 grams of calcium (Ca) and 5.5 grams of sulfur (S) are created, _________ grams of CaS were decomposed. Please fill in the NUMBER only in the box below.

Answer 1

If we look at the decomposition of a binary compound into it's constituent elements, such as AB => A + B, then the law of conservation of matter must apply. Thus, the mass of the products must equal the mass of the reactants (in a closed or isolated system).

CaS ==> Ca + S

x g ........9.3 g + 5.5 g

x = 14.8 g CaS