Ok I just thought of a simpler way. I think that you can simply use the ratio between the energy values and the moles.
2 mol of H2O2 will result in q = -196 kJ.
Therefore, what will q be when there are "x" mol of H2O2. Calculate "x" moles using the mass of H2O2 given. Then use the ratio.
Pretty easy actually, there's probably a proper way to do it. But this way is faster. :p