Molar mass of Na = 23 g/mol
Given mass of Na added , m = 0.330 g
So number of moles of Na = mass/molar mass
                                    Â
= 0.330 g / 23 (g/mol)
                                    Â
= 0.0143 mol
The amount of heat liberated by the reaction of 0.0143 mol of Na
is 3430 J
The balanced reaction is : 2Na(s) + 2HCl(aq) ------->
2NaCl(aq) + H2 (g)
The amount of heat liberated by the reaction of 2 mol of Na is M
J
M = ( 2x3430)/0.0143
   = 479.7x103 J
   = 479.7 kJ
Therefore the enthalpy of the reaction = -479.7 kJ
