Question

Elements A and B react according to the following equation:

4A+B2→2A2B

The molar mass of A is 12g/mol. The molar mass of B is 4g/mol. The molar mass of A2B
is 28g/mol. When the goal of the reaction is to produce 112g of the product, how many grams of reactant A should be present initially?

(1 point)
Responses

16
16

24
24

48
48

96

Answers

GPT 3.5
48

To solve this problem, we need to first calculate the molar ratio between A and A2B in the reaction equation.

From the balanced equation, we can see that 4 moles of A react with 1 mole of B2 to produce 2 moles of A2B.

Next, we need to calculate the molar mass ratio between A and A2B. The total molar mass of A and B2 is 12g/mol + 8g/mol = 20g/mol, and the molar mass of A2B is 28g/mol. Therefore, the molar mass ratio of A to A2B is 20g/mol:28g/mol = 5:7.

By combining the molar ratio and molar mass ratio, we find that 20g of A reacts with 28g of A2B. To produce 112g of A2B, we need 80g of A.

Therefore, the answer is 48g of reactant A should be present initially.