Help me with this easy ques pls?

I'm not completely sure about this answer but ill explain how I got it. So you know that the 3.25g sample of sodium hydroxide rose the temperature of 100.0g of water 8.1C(32.0-23.9). The specific heat of water is 4.184J/g. To find how many J it took to do that you multiply the m of the water by its heat capacity by the change in temp. 100.0x4.184x8.1=3389J. The answer is in kJ so divide by 1000 so you have 3.389kJ. You know know that it took 3.25g of sodium hydroxide to put out 3.389kJ of energy. The answer is in mol of NaOH so divide 3.25 by its molar m to find how many moles it is. 3.25/(22.99+1.008+16.00)=.0813mol of NaOH. To find the amount of energy it took per mol of NaOH divide the kJ of energy put out by the moles of NaOH (3.389kJ/.0813)=41.69kJ/mol NaOH