1) The volume of a balloon is 225 ml. The temperature of the balloon is 20°C. If a scientist
drops the temperature by 10°C, what is the new volume?

217.3ml

Explanation:

In order to answer this question, we apply Charles' law, which states that at a constant pressure, the volume of a fixed mass of gas (V) is directly proportional to the temperature (T).

That is, V = KT

K = V/T

Hence, V1/T1 = V2/T2

Where; V1 = initial volume

V2 = final volume

T1 = initial temperature

T2 = final temperature

The unit of temperature must be in Kelvin (K), which is the unit for absolute temperature.

To convert Celsius (°C) to Kelvin (K), we use; K = C + 273

Hence, T1 = 273 + 20 = 293K

T2 = 273 + 10 = 283K

V1 = 225ml

V2 = ?

Using the formula; V1/T1 = V2/T2

225/293 = V2/283

We cross multipy;

293 × V2 = 283 × 225

293V2 = 63675

We divide both sides by 293

V2 = 63675/293

V2 = 217.32

Hence, the new volume (V2) is 217.3ml