Question

An additional 5.5 moles of nitrogen are added to a flexible container already holding 2.5 moles. The container expands to 310 mL. What was the volume before the extra gas was added?

Answer 1

`97\text{ mL}`

Step-by-step explanation:

Here, we want to get the initial volume of the gas

From Avogadros' law, we know that the volume of a gas is directly proportional to the number of moles of the gas at constant temperature and pressure

Mathematically:

`(V_1)/(n_1)\text{ = }(V_2)/(n_2)`

where:

V1 is the initial volume that we want to calculate

V2 is the final volume which is 310 mL

n1 is the initial number of moles which is 2.5 moles

n2 is the final number of moles which is 2.5 + 5.5 = 8 moles

We can now proceed to substitute the values as follows:

`\begin{gathered} (V_1)/(2.5)\text{ = }(310)/(8) \\ \\ 8\text{ }*\text{ V}_1\text{ = 2.5 }*\text{ 310} \\ V_1\text{ = }\frac{2.5\text{ }*\text{ 310 }}{8} \\ \\ V_1\text{ = 96.875 mL} \end{gathered}`