Question

Question 1 how many moles of helium are found in a balloon that contains 5.5 l of helium at a pressure of 1.15 atm and a temperature of 22.0 ºc?

Answer 1

Answer : The number of moles of helium gas found in a balloon are 0.26 moles.

Explanation :

To calculate the moles of helium gas, we use the equation given by ideal gas :

PV = nRT

where,

P = Pressure of helium gas = 1.15 atm

V = Volume of the helium gas = 5.5 L

n = number of moles of helium gas = ?

R = Gas constant = $0.0821\text{ L.atm }mol^{-1}K^{-1}$

T = Temperature of helium gas = $22.0^oC=273+22.0=295K$

Putting values in above equation, we get:

$1.15atm\times 5.5L=n\times 0.0821\text{ L.atm }mol^{-1}K^{-1}\times 295K\\\\n=0.26mol$

Therefore, the number of moles of helium gas found in a balloon are 0.26 moles.

Answer 2

Using pv=nRT
T= 22+273 K
P=1.15 Pa
R=8.31
V =5.5... (u did not write the unit so...)

Therefore n,mole= (1.15×5.5) ÷ (273+22)(8.31)