Answer to Question #114561 in General Chemistry for Paola

Question

Calculate the pH after the addition of 35 mL of 0.10 M NaOH to 30 ml. 0.10 HCN,

Answer 1

NaOH+HCN--> NaCN + H2O;

OH^-+H⁺-->H2O

n(NaOH)=0.1*0.035=0.0035 mol;

n(HCN)=0.1*0.03=0.003 mol;

[OH^-]=0.0035-0.003=5*10^-4;

pH=14+lg[OH^-]=10.69