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

The answer for the following problem is mentioned below.

• Therefore the final  moles of the gas is 14.2 × $10^{-4}$ moles.

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

$\frac{V_{1} }{V_{2} }$ = $\frac{n_{1} }{n_{2} }$

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;

   $\frac{230}{860}$ = $\frac{3.8 * 10^-4}{n_{2} }$

  $n_{2}$ = 14.2 × $10^{-4}$ moles

Therefore the final  moles of the gas is 14.2 × $10^{-4}$ moles.

Answer 2

Answer:

1.0 × 10-4 mol

Or just A. The first one

Explanation:

Just did it on eg