1st part
#"Molar mass of " H_2SO_4 "=98g/"mol" #
#"Strngth of "H_2SO_4" solution""=7.5M#
#=7.5"mol"/Lxx98g/"mol"=
735g/L#
#"Volume of acid soln containing " 150g H_2SO_4=(150g)/(735g/L)=0.2041L=204.1mL#
2nd Part
#V_1->"Initial volume of HCl solution"=?#
#S_1->"Initial Strngth of HCl solution"=2.5M#
After dilution
#V_2->"Final volume of HCl solution"=350mL#
#S_2->"Fimal Strength of HCl solution"= 1.15M#
So
#V_1S_1=V_2xxS_2=>V_1xx2.5=350xx1.15#
#V_1=(350xx1.15)/2.5=161mL#