When 0.782g of sodium metal is added to an excess of hydrochloric acid,

Question

When  g of sodium metal is added to an excess of hydrochloric acid,  J of heat are produced. What is the enthalpy of the reaction as written?

Answer 1

As written, you would have...

2Na(s) + 2HCl(aq) ==> 2NaCl(aq) + H₂(g)

0.782 g Na x 1 mol Na/23 g = 0.034 moles Na

8130 J/0.034 mol Na x 2 mol Na = 478,235 J for the reaction as written = 478 kJ for reaction as written