1-30 Identify reactants and products of a chemical reaction

1-30-1. A mixture contains 25.0 g of substance X and 10.0 g of substance Y. A few minutes later, due to a chemical change, it is found that the mixture now contains 30.0 g of substance X and 5.0 g of substance Y. For the reaction described here...
A. X is the reactant and Y is the product
B. Y is the reactant and X is the product
C. Both X and Y are reactants
D. Both X and Y are products

1-30-2. Consider the pictorial representation of a chemical change shown below. Which of the following is not a product of the reaction?
A. C₂H₂, B. H₂O, C. CO₂

1-30-3. Consider the chemical equation for the hydrogenation of acetylene:
C₂H₂ + 2H₂ → C₂H₆
Which of these is the formula of a reactant in this reaction?
A. C₂H₂, B. 2H₂, C. C₂H₆