Question

A balloon containing helium gas expands from 230

mL to 860 mL as more helium is added. What was
the initial quantity of helium present if the
expanded balloon contains 3.8 x 10-4 mol,
assuming constant temperature and pressure?
Which of the variables are known?
DONE

Answer 1

1.0 × 10-4 mol

Or just A. The first one

Step-by-step explanation:

Just did it on eg

Answer 2

The answer for the following problem is mentioned below.

• Therefore the final moles of the gas is 14.2 ×
  `10^(-4)` moles.

Step-by-step explanation:

Given:

Initial volume (
`V_(1)`) = 230 ml

Final volume (
`V_(2)`) = 860 ml

Initial moles (
`n_(1)`) = 3.8 ×
`10^(-4)` moles

To find:

Final moles (
`n_(2)`)

We know;

According to the ideal gas equation;

P × V = n × R × T

where;

P represents the pressure of the gas

V represents the volume of the gas

n represents the no of the moles of the gas

R represents the universal gas constant

T represents the temperature of the gas

So;

V ∝ n

`(V_(1) )/(V_(2) )` =
`(n_(1) )/(n_(2) )`

where,

(
`V_(1)`) represents the initial volume of the gas

(
`V_(2)`) represents the final volume of the gas

(
`n_(1)`) represents the initial moles of the gas

(
`n_(2)`) represents the final moles of the gas

Substituting the above values;

`(230)/(860)` =
`(3.8 * 10^-4)/(n_(2) )`

`n_(2)` = 14.2 ×
`10^(-4)` moles

Therefore the final moles of the gas is 14.2 ×
`10^(-4)` moles.