Question

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A laboratory has a 3.0 mol sample of pure carbon and a 3.0 mol sample of pure helium. How many more grams of carbon do they have than grams of helium?
Answer Choices:
The carbon sample would have the same mass as the helium sample.

The carbon sample would have two times the mass of the helium sample.

The carbon sample would have three times the mass of the helium sample.

The carbon sample would have six times the mass of the helium sample.

Answer 1

The correct answer is; 'The carbon sample would have three times the mass of the helium sample'.

Step-by-step explanation:

Number of moles of carbon = 3.0 moles

Mass of 3 moles of carbon ,m=
`3 moles* 12 g/mol = 36 g`

Number of moles of helium = 3.0 moles

Mass of 3 moles of helium,m' =
`3 moles* 4 g/mol = 12 g`

Grams of carbon do we have more than grams of helium:

Mass of carbon > Mass of helium

`(m)/(m')=(36 g)/(12 g)=3`

m = 3m'

The carbon sample would have three times the mass of the helium sample

Answer 2

protons + and electrons - must be equal

3 moles of C has a mass of 36, 3 moles of He is 12

so the answer is :
The carbon sample would have three times the mass of the helium sample

hope this helps