Suppose an unknown compound XY has an X-to-Y mass ratio of 4.0. If decomposition of compound XY gives 12.0 grams of X, then how many grams of Y must form? Suppose an unknown compound XY has an X-to-Y mass ratio of 4.0. If decomposition of compound XY gives 12.0 grams of X, then how many grams of Y must form? 12.0 grams 3.0 grams 48.0 grams 4.0 grams none of the above

Answer:then the number of grams of Y that must form is 3

Step-by-step explanation:

Suppose an unknown compound XY has an X-to-Y mass ratio of 4.0, it means that

X/Y = 4

Crossmultiplying,

X = 4Y

If decomposition of compound XY gives 12.0 grams of X, then the number of grams of Y that must form would be

X = 4Y

Substituting X = 12 into the equation, it becomes

12 = 4Y

Y = 12/4 = 3 grams