How Much Energy Is Released When Mixing HCl and NaOH?

[JessicaHelena]

Homework Statement

The enthalpy of neutralization for the reaction of a strong acid with a strong base is -56 kJ/mol of water produced. How much energy will be released when 195.0 mL of 0.400 M HCl is mixed with 155.5 mL of 0.500 M NaOH?

Homework Equations

c=n/V

The Attempt at a Solution

to get n (from c=n/V), we can do c*V.
In this case, the total moles is then 0.4*.195 + .1555 * 0.5 moles
and multiplying that by -56kJ/mol gave me -8.722 kJ, but that's wrong... Why?

 

[BvU]

Do all moles react ? Write out the 'reaction' equation and underneath put the # of moles for each.