Question

4. A gas is collected at 20.0 °C and 755.0 mmHg. When the

temperature is changed to -5 °C, what is the resulting pressure?

Answer 1

`690.61\text{ mmHg}`

Step-by-step explanation:

Here, we want to get the resulting pressure

According to the pressure law, temperature and pressure are directly proportional

Mathematically:

`(P_1)/(T_1)\text{ = }(P_2)/(T_2)`

where:

P1 is the initial pressure which is 755 mmHg

P2 is the final pressure which is not given

T1 is the initial temperature which we will convert to Kelvin by adding 273.15 K : 20 + 273.15 = 293.15 K

T2 is the final temperature which is -5 + 273.15 = 268.15 K

Substituting the values, we have it that:

`\begin{gathered} (755)/(293.15)\text{ = }(P_2)/(268.15) \\ \\ P_2\text{ = }(755*268.15)/(293.15)\text{ = 690.61 mmHg} \end{gathered}`