Question

326L

Answer 1

Answer:

Final number of moles = 0.675 mol

Mass = 2.7 g

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