5070 M/J 2012 MCQ paper 11 discussions

[maee sha]

9) 15.0 cm3 of 1.0 mol / dm3 potassium hydroxide just neutralise 20.0 cm3 of a solution of nitric acid.
What is the concentration of the acid?
A 0.75 mol / dm3
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0.75Mol/dm3 is the correct answer according to marking scheme. Can Anyone PLease show me the step by step working to find answer?

 

[Adiizz]

1000cm3--> 1 mol KOH
in 15 cm3 u will have 15/1000= 0.015mol KOH
to neutralise 20cm3 of acid we need 0.015 mol of KOH
so in 1000cm3 of acid we require (0015/20)*1000=o.75
answer is o.75mol/dm3........

hope u understand!

 

[maee sha]

thank u Adiizz ...
everytime i forget that 1000cm3 <-->1 mol