8. In standardizing a solution of HCl, it is found that 47.26ml of the acid are equivalent to 1.216g of pure Na2CO3. What is the normality of the acid? A. 0.4855N B. 0.3540N C. 0.5020N D. 0.3902N 9. A 1 gram sample of impure K2CO3 is taken for analysis. The solution of the dissolved sample required 58.10mL of 0.14NHCl. However, 0.65mL of NaOH was used for back titration (1 mLHCl is equivalent to 2.60mLNaOH ). Calculate the purity of the sample expressed as percent K2O. A. 38.14% B. 40.23% C. 34.4% D. 6.67% 10. A super phosphate fertilizer was analyzed for phosphorus. A 0.5414gram sample produce 0.1277g of Mg2P2O7 residue upon ignition of the magnesium ammonium phosphate precipitate. The percentage of P2O5 present in the sample is A. 20.5% B. 18.20% C. 15.04% D. 14.02%