Question #66b6c

1 Answer
Jul 15, 2017

"gas added" = 11.9gas added=11.9 "mol"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)V1n1=V2n2 (constant temperature and pressure)

Our known quantities are:

  • V_1V1: 8.158.15 "L"L

  • n_1n1: 9.519.51 "mol"mol

  • V_2V2: 18.318.3 "L"L

We can plug these into the equation and solve for the final quantity, n_2n2:

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"