Question

If a 23.7 mL solution of H2SO4 has a concentration of 0.100 M, what is its pH? Also, how
many grams of H2SO4 are in the solution?

Answer 1

Solution.

$V(H_2SO_4)=23.7mL=0.0237L;$

$M(H_2SO_4)=0.100M;$

$[H_3O^+]=[H_2SO4]=0.100M;$

$pH=-lg[H_3O^+]=-lg(0.100)=1;$

$\nu(H_2SO_4)=\dfrac{m}{Molecular weight};\implies m=\nu(H_2SO_4)\sdot Molecular weight;$

$Molecular weight=98g/mol;$

$\nu(H_2SO_4)=V(H_2SO_4)\sdot M; \nu=0.0237L\sdot0.100mol/L=0.00237mol;$

$m=0.00237mol\sdot 98g/mol=0.232g;$

Answer: $pH=1;$

$m=0.232g.$