Question

Liquid $1$ and Liquid $2$ react to produce a solid and a gas. Which of the following expressions correctly shows how to determine the mass of the gas?

• A. $(\text{mass of Liquid}1+\text{mass of Liquid}2)-\left(\text{mass of solid}\right)$
• B. $(\text{mass of Liquid}1+\text{mass of Liquid}2)+\left(\text{mass of solid}\right)$
• C. $(\text{mass of Liquid}1\times \text{mass of Liquid}2)÷\left(\text{mass of solid}\right)$
• D. $(\text{mass of Liquid}1-\text{mass of Liquid}2)-\left(\text{mass of solid}\right)$

Answer 1

The correct option is A $(\text{mass of Liquid}1+\text{mass of Liquid}2)-\left(\text{mass of solid}\right)$

According to the law of conservation of mass :

(mass of liquid 1) + (mass of liquid 2) =(mass of solid) + (mass of gas)

$\therefore$ Mass of gas = mass of Liquid 1 + mass of Liquid 2 - mass of solid.

The correct option is A.