Question

A weather balloon is inflated with helium. The balloon has a volume of $100m^3$ and it must be inflated to a pressure of $0.10atm$. If $50L$ gas cylinders of helium at a pressure of $100atm$ are used, how many cylinders are needed? Assume that temperature is constant.

• A. $2$
• B. $3$
• C. $4$
• D. $1$

Answer 1

The correct option is A $2$

If the cylinders were at 1.00 atm, they would contain 50.00 L each, so at 100.0 atm they contain 5000. L each.

$1m^3=1000L$,

So $100.0m^3=1.000\times {10}^{5}L$.

Since the pressure in the balloon is only 0.10 atm, though, the gas volume equals only $1.000\times {10}^{4}L$at 1 atm.

(1.000 × 10⁴ L) / (5000. L/cylinder) = 2.00 cylinders.

$\frac{1.000\times {10}^{4}L}{5000L}$ /cylinder $=2$ cylinders