Answer
Number of moles = 0.0025 mol
Explanation:
Given that,
The volume of He at STP is 56.0 ml
Part a:
Find the mole
According to the standard conversion
1 mol = 22.4L
Firstly, we need to convert 56.0ml to L
This can be done by dividing by 1000
56.0mL = 0.056L
1 mole = 22.4L
x mole = 0.056L
Cross multiply
1 * 0.056 = x * 22.4
0.056 = 22.4x
Divide both sides by 22.4
x = 0.056 / 22.4
x = 0.0025 mole
Hence, the mole of Helium is 0.0025 moleHe