A 12. 2 g sample of X reacts with a sample of Y to form 78.9 g of XY. What is the mass of Y that reacted?

1 Answer
Jan 26, 2017

Answer:

#"Mass"# #=# #78.0*g-12.2*g=?#

Explanation:

All chemical reactions CONSERVE mass. What does this mean?

It means that if I start with #10 *g# of reactants, from all source, AT MOST I can get #10*g# of product.

#"Garbage in equals Garbage out!"#

Here I finished with a #78.9*g# mass of #XY#. There were #12.2*g# of #X#. And the balance must represent the mass of #Y#.