Question

James burnt 25 g of calcium in air to produce calcium oxide according to the reaction: 2Ca(s) + O_2(g) 2CaO(s). After the reaction, James found that the mass of calcium oxide produced was 35 g. Given this information, calculate the weight of the oxygen reacted to make the compound calcium oxide.

A) 10 g
B) 20 g
C) 35 g
D) 45 g

Answer 1

The weight of oxygen reacted to make calcium oxide is 10 g.

Step-by-step explanation:

To calculate the weight of oxygen reacted to make calcium oxide, we need to find the difference in mass before and after the reaction. James started with 25 g of calcium and ended with 35 g of calcium oxide. The difference in mass, 10 g, represents the weight of the oxygen reacted to form calcium oxide. Therefore, the correct answer is A) 10 g.