# Question Video: Identifying the Purpose of a Balance Chemistry

What would the following laboratory setup be used for? [A] Measuring the volume of a liquid or gas. [B] Measuring the temperature of a substance. [C] Measuring time. [D] Measuring the pH of a solution. [E] Measuring the mass of a substance.

02:23

### Video Transcript

What would the following laboratory setup be used for? (A) Measuring the volume of a liquid or gas. (B) Measuring the temperature of a substance. (C) Measuring time. (D) Measuring the pH of a solution. Or (E) measuring the mass of a substance.

In the lab, students, chemists, scientists, or other professionals often need to make measurements. We can measure the volume of liquid or gas, reactant or product, or the mass of a solid substance taking part in or being produced from a reaction. We can measure temperature or time that has elapsed, pH of a solution, and many other variables. The diagram given shows the lab setup of an electronic mass balance and a vessel, in this case a beaker, used to hold a substance whose mass will be measured.

A beaker might be used when the mass of a liquid is being determined. But more commonly, a watch glass or a weighing boat will be used when the mass of a solid is being determined, especially if it is a small amount of solid. This electronic mass balance is a top-loading mass balance. Top-loading balances tend to measure masses to the nearest gram or tenth of a gram or one one hundredth of a gram. They are not as accurate as analytical balances, which can measure to the nearest one ten thousandth of a gram.

What would the following laboratory setup be used for? The answer is (E), measuring the mass of a substance.

Let’s briefly remind ourselves the names of the apparatus and equipment used in answer options (A) through to (D). There are a variety of glass we use to measure liquids, for example, burets and graduated cylinders, which are used to measure more accurate volumes, and beakers, which are used to measure approximate volumes. For gases, we use a gas syringe. To measure temperature, we typically use a thermometer. We use a clock or stopwatch to measure the passing of time and a pH meter to measure the acidity or basicity of a solution.