Answer:
Final number of moles = 0.675 mol
Mass = 2.7 g
Step-by-step explanation:
Given data:
Initial volume of gas = 2.00 L
Final volume of gas = 2.70 L
Initial number of moles = 0.500 mol
Final number of moles = ?
Solution:
Formula:
V₁/n₁ = V₂/n₂
V₁ = Initial volume
n₁ = Initial number of moles
V₂ = Final volume of gas
n₂ = Final number of moles
Now we will put the values in formula.
2.00 L /0.500 mol = 2.70 L / n₂
n₂ = 2.70 L× 0.500 mol /2.00 L
n₂ = 1.35 L.mol / 2.00 L
n₂ = 0.675 mol
B)
Grams of helium added = ?
Solution:
Mass = number of moles × molar mass
Mass = 0.675 mol× 4 g/mol
Mass = 2.7 g