Chemistry

3)
a)Calculate the number of moles of CO2 molecules in 11.0 g of carbon dioxide.
b) Calculate the number of moles of C atoms in 11.0 g of carbon dioxide.
c) Calculate the number of moles of O atoms in 11.0 g of carbon dioxide.

>I'm not sure how the answer for 3b= 0.25moles and for 3c= 0.5moles

Reply 1

EricPiphany

For each mole of carbon dioxide there is one mole of carbon and two moles of oxygen. Why?

Spoiler

Reply 2

differentiate1

Mass/molar mass(mr) = moles so for a) the formula would be mass of CO2/(mr of c)+(mr of o2)

Reply 3

leafcannon

Original post by Rhea7777

First, look at this equation:

C + O₂ -> CO₂

In this equation, you can see that 1 mole of C and 1 mole of O₂ (which is the same as 2 moles of O) makes 1 mole of CO₂.

In case you didn't get the answer to a, you can find out the relative formula mass of CO₂ by adding the relative atomic masses of C and O₂:

C = 12
O₂ = 2 x 16 = 32
CO₂ = 12 + 32 = 44
Moles of CO₂ = 11/44 = 0.25mol

Simply multiply this by the number of moles in the equation to get:

C = 0.25 x 1 = 0.25mol
O = 0.25 x 2 = 0.5mol