Q90E

Question

What volume of a 0.00945 M solution of potassium hydroxide would be required to titrate 50.00 mL of a sample of acid rain with a H2SO4 concentration of    1.23×10-4M

\({{\rm{H}}_2}{\rm{S}}{{\rm{O}}_{4({\rm{aq}})}}{\rm{  +   2KO}}{{\rm{H}}_{({\rm{aq}})}}{\rm{ }} \to {\rm{ }}{{\rm{K}}_2}{\rm{S}}{{\rm{O}}_{4({\rm{aq}})}}{\rm{  +   2}}{{\rm{H}}_2}{{\rm{O}}_{{\rm{(l)}}}}\)

Step-by-Step Solution

Verified
Answer

1.30 ml of potassium hydroxide will be required to titrate 50.00 mL of acid rain sample with sulphuric acid.

1Step 1: Number of moles of sodium hydroxide and oxalic acid

It is given that the concentration of sulphuric acid is 1.23×10-4M and the volume is 50 ml.

The number of moles can be calculated by the mole concept formula that is:

the number of moles = \({\rm{volume }} \times {\rm{ concentration}}\)

the number of moles = 50×1.23×10-4M =6.15×10-3 moles

Now, as 1 moles of sulphuric acid reacts with 2 moles of \({\rm{KOH}}\), thus the number of moles of potassium hydroxide will be 6.15×10-3 moles×2=0.0123 moles

2Step 2: Volume of potassium hydroxide

It is given that the concentration of potassium hydroxide is 0.00945 M and the moles of \({\rm{KOH}}\)from above calculation is 0.0123 moles, then the volume of \({\rm{KOH}}\) will be calculated as

\({\rm{Volume  =   }}\frac{{{\rm{moles}}}}{{{\rm{concentration}}}}\)

\({\rm{Volume  =  }}\frac{{0.0123}}{{0.00945}}{\rm{  =   1}}{\rm{.30 mL}}\)