Calculate the consentration of CN- and the PH for a solution that is made by mixing 50mL of 0.1M HCIO4 with 4.2mL of 0.438M NaCN. Assume HCIO4 to be a strong acid, NaCN to be a strong electrolyte ( dissociates completely ) and the pKa for HCN to be 9.21?