ΔQ has units of joules .The base unit of mass is the kilogram - 1 gram is 10^-3 kg and you need to stick to this.
Units of ΔT would be kelvins obviously.
To get a consistent equation where the units on both sides must match up you would need c to have units of Jkg−1K−1 - you got the units of Q wrong to start off with.
But, in the question, it says the specific heat capacity of water is 4.18 JK(-1)g(-1) In a situation like this, do I use the mass in g instead of in Kg?
gotcha. so basically I use whatever mass type is specified in the specific heat capacity?
i think youre getting confused
q = mct
m = mass of liquid (so this would be in grams) t = change in temperature
C is a specific constant to the liquid youre calculating energy for, e.g. for water itd be 4.2 J g^-1 K^-1, you just put the number into the formula in the exam.. infact you can do that for all 3 quantities, you only need to specifiy the unit for the end energy transferred which will always be in joules
m = mass of liquid (so this would be in grams) t = change in temperature
C is a specific constant to the liquid youre calculating energy for, e.g. for water itd be 4.2 J g^-1 K^-1, you just put the number into the formula in the exam.. infact you can do that for all 3 quantities, you only need to specifiy the unit for the end energy transferred which will always be in joules
yeah I think I am too
oh ok so they won't expect me to convert anything?
i'm not 100% sure if this is correct but apparently you didn't need the q=mct equation... you were meant to use c and the other numbers they gave you, rearrange it in some way and you'd get delta S. So then you'd use the G=H - TS equation to work out the temperature... I got a strange answer when I used q=mct, but my friend told me that they did what I said above and they got 63.9 or something. I don't really know if that's correct, I just thought i'd put it out there
gotcha. so basically I use whatever mass type is specified in the specific heat capacity?
Yes. Or whatever else is specified in the specific heat capacity. What you really need, with the specific heat capacity, is the units for whatever value you're given. Then just make sure you are working with that value so that your units reduce down to the unit you want your final answer in.