Question

define the term limiting reagent point out the limiting reagent when 20g of NaOH react with 98g of sulphuric acid

Answer 1

Explanation:

H

2

SO

4

+2NaOH→Na

2

SO

4

+2H

2

O

The molar masses of H

2

SO

4

and NaOH are 98 g/mol and 40 g/mol respectively.

Number of moles is the ratio of mass to molar mass.

Number of moles of H

2

SO

4

=

98

49

=0.5 moles

Number of moles of NaOH =

40

80.0

=2 moles

0.5 moles of H

2

SO

4

will react with 2×0.5=1.0 mole of NaOH.

2−1=1 mole of NaOH will remain unreacted. This corresponds to 1×40=40g.