30cm3 of 2.0M hydrochloric acid completely reacts with 5.0g of impure zinc carbonate. Calculate the per centage purity of zinc carbonate. (Zn=65, C=12, O=16)
Step I
Write a balanced equation for the reaction between hydrochloric and zinc carbonate
ZnCo3 (s) + 2HCL2(aq) ZnCl (aq) + CO2 (g) + H2O(l)
Step II
Calculate the number of moles of hydrochloric acid
Number of moles of hydrochloric acid = molarity x volume in L
   
= X 30
   
     
=moles