Question

Sample X has a mass of 22.7 g and reacts with sample Y to form sample XY with a total mass of 86.9 g. What is the mass of sample Y?

Answer 1

Answer:

$\large \boxed{\text{64.2 g}}$

Explanation:

                 X  +  Y ⟶ XY

mass:  22.7 g   x     86.9 g

According to the Law of Conservation of Mass, the mass of the product must equal the mass of the reactants.

$\begin{array}{rcl}\text{22.7 g} + x & = & \text{86.9 g}\\x & = & \text{86.9 g} - \text{22.7 g}\\& = & \textbf{64.2 g}\\\end{array}\\\text{The mass of Y is \large \boxed{\textbf{64.2 g}} }$