Question

How many moles of 02 are consumed when 0.770 mol of magnesium burns in excess oxygen?

Answer 1

2Mg + O2 -----> 2MgO

2 mol Mg reacts with 1 mol O2.

0.770 mol Mg x (1 mol O2 / 2 mol Mg) = 0.385 mol O2

Answer 2

Answer: 0.385 moles

Explanation:-

Combustion is a type of chemical reaction in which a substance is reacted with oxygen.

The balanced chemical reaction between magnesium and oxygen is:

`2Mg+O_2 \rightarrow 2MgO`

From the stoichiometry:

2 moles of magnesium react with = 1 mole of oxygen

Thus 0.770 moles of magnesium react with =
`(1 )/(2)* 0.770=0.385` moles of oxygen

Thus 0.385 moles of
`O_2` are consumed when 0.770 mol of magnesium burns in excess oxygen.