Equal volumes of 1 M ${\mathrm{HNO}}_3$   and 1 M ${\mathrm{H}}_3{\mathrm{PO}}_4$ are neutralized by dilute NaOH solution. If xand y K.cals are the heats liberated in the neutralization of HNO₃ and ${\mathrm{H}}_3{\mathrm{PO}}_4$respectively, the relation between x and y (assume ${\mathrm{H}}_3{\mathrm{PO}}_4$ is completely ionized)