Question

Question #66b6c

Answer 1

`"gas added" = 11.9` `"mol"`

Explanation:

To solve this, we can use the quantity-volume relationship of gases.

According to Avogadro's hypothesis:

The number of moles of a gas is directly to proportional to the volume the gas occupies.

And, under constant temperature and pressure conditions, we get the equation

`(V_1)/(n_1) = (V_2)/(n_2)` (constant temperature and pressure)

Our known quantities are:

• `V_1`: `8.15` `"L"`

• `n_1`: `9.51` `"mol"`

• `V_2`: `18.3` `"L"`

We can plug these into the equation and solve for the final quantity, `n_2`:

`n_2 = (n_1V_2)/(V_1) = ((9.51color(white)(l))(18.3cancel("L")))/(8.15cancel("L")) = color(red)(21.4` `color(red)("mol"`

We're asked to find the number of moles needed to be added: so we subtract the initial amount from the final amount:

`"gas added" = color(red)(21.4` `color(red)("mol"` `- 9.51` `"mol"` `= color(blue)(11.9` `color(blue)("mol"`