Some Basic Concepts Of Chemistry Question 40
Question: The concentrated sulphuric acid that is peddled commercial is 95% $ H _2SO _4 $ by weight. If the density of this commercial acid is $ 1.834gc{m^{-3}} $ , the molarity of this solution is
Options:
A) 17.8 M
B) 12.0.M
C) 10.5 M
D) 15.7 M
Show Answer
Answer:
Correct Answer: A
Solution:
[a] 95% $ H _2SO _4 $ by weight means 100g $ H _2SO _4 $ solution contains 95g $ H _2SO _4 $ by mass. Molar mass of $ H _2SO _4~=98gmo{l^{-1}} $ Moles in $ 95g=\frac{95}{98}=0.969 $ mole Volume of $ 100g,H _2SO _4 $ $ =\frac{mass}{density}=\frac{100g}{1.834gc{m^{-3}}} $
$ =54.52cm^{3}=54.52\times {10^{-3}}L $
$ Molarity=\frac{\text{Moles of}solute}{\text{Voime of solute in L}} $
$ =\frac{0.969}{54.52\times {10^{-3}}}=17.8M $
