Sharon combines potassium (K) and water (H2O), producing potassium hydroxide (KOH) and hydrogen(H2), as shown in the chemical equation.

Question

2K + 2H2O → 2KOH + H2

She records the total mass of potassium and water in the lab before combining them. The table shows her measurements.

Sharon predicts that the mass of the products will be 60 g. According to the law of conservation of matter, is Sharon’s prediction correct or incorrect? Why or why not?

(1 point)
Responses

Her prediction is incorrect because the law of conservation of matter states that matter can neither be created nor destroyed, so the mass of the products will be 50 g.
Her prediction is incorrect because the law of conservation of matter states that matter can neither be created nor destroyed, so the mass of the products will be 50 g.

Her prediction is correct because the law of conservation of matter states that the products of a reaction have more mass than the reactants.
Her prediction is correct because the law of conservation of matter states that the products of a reaction have more mass than the reactants.

Her prediction is incorrect because the law of conservation of matter states that some mass is lost in a chemical reaction, so the mass of the products will be less than 50 g.
Her prediction is incorrect because the law of conservation of matter states that some mass is lost in a chemical reaction, so the mass of the products will be less than 50 g.

Her prediction is correct because the law of conservation of matter states that matter can neither be created nor destroyed in a chemical reaction.
Her prediction is correct because the law of conservation of matter states that matter can neither be created nor destroyed in a chemical reaction.

Answer 1

The correct response is:

Her prediction is correct because the law of conservation of matter states that matter can neither be created nor destroyed in a chemical reaction.

According to the law of conservation of matter, the total mass of the reactants (potassium and water) before the reaction must equal the total mass of the products (potassium hydroxide and hydrogen) after the reaction. If Sharon recorded the total mass of potassium and water before the reaction and calculated it to be 60 g, then the total mass of the products should also equal 60 g, assuming no mass was lost during the reaction. Thus, her prediction of 60 g is correct.