[SteveJobs]

I missed the entire thermochemistry unit at school (i was away on a school trip) so I'm not sure that I'm going about these questions correctly.

I have:

100 mL (100g) of Distilled Water
1.96g of NaOH pellets (solid)

the water had an initial temperature of 21.0°C
when the NaOH was added to the water, it reached a maximum temperature of 28.0°C

1. Find the change in temperature

28.0-21.0= 7.0°C


2. Find the number of joules of energy absorbed by the water (released by the NaOH)


ΔH=msΔT = 100g*4.18(J/g°C)*7.0= 2926J


3. Find the number of Joules of heat energy released per gram of NaOH

2926J/1.96g = 1493J/1g


Find ΔH in kJ/mol NaOH

I have no idea how to do this one, so an explanation would be wonderful.

Also, how does one determine the specific heat of a substance? Is there a formula, or...?

Thanks!

[Borek]

1g of NaOH - how many moles?

[SteveJobs]

1g of NaOH is 0.025 mol

[Borek]

And you still have problems converting J/g to J/mol?

[SteveJobs]

Yes, I understand. It's kind of embarrassing how simple that was. Thank-you very much for your assistance!