You guys mind assisting me with a few problems
I understand others need help so I ranked them in order that I am having most problems with. I dont expect to get help with all. Just hoping one will have knowledge of one of them.
Problem 1Under constant-volume conditions the heat of combustion of benzoic acid (HC7H5O2) is 26.38 kJ/g. A 1.570-g sample of benzoic acid is burned in a bomb calorimeter. The temperature of the calorimeter increases from 22.15°C to 26.20°C.a) What is the total heat capacity of the calorimeter? Ok so looking at this I see 26.38 kJ/g. Now isn't kJ/g constant-pressure calorimeter? Would I go about coverting the said problem by doing (26.38 kJ/g)(1.570g)=41.42kJ, then (ANS)(4.05 C)=167.8 kJ/C?
What is throwing me off here is that it was burned in a bomb calorimeter whos formula is qrxn=-Ccal*t. The way I worked out that problem just now is constant-pressure. Someone mind explaining
b) A 1.400-g sample of a new organic substance is combusted in the same calorimeter. The temperature of the calorimeter increases from 21.84°C to 26.62°C. What is the heat of combustion per gram of the new substance?Work out the same way using 26.38 kJ/g and new givens?
Problem 2Consider the following reaction:
CH3OH(g) → CO(g)+ 2H2(g) ΔH = +90.7 kJ (a) Calculate the amount of heat transferred when 1.51 kg of CH3OH(g) are decomposed by this reaction at constant pressure.Ok I solved and came up with the answer of 4.28E3 kJ. This is not what threw me off.
b)For a given sample of CH3OH, the enthalpy change on reaction is 57.9 kJ. How many grams of hydrogen gas are produced?Alright so how do I find the amount of grams with just 57.9kJ? I can't seem to figure out how to flip it or plug in the kJ or if I am suppose to use the information in (a).
Problem 3(a) When a 9.55-g sample of solid sodium hydroxide dissolves in 1.00E2 g of water in a coffee-cup calorimeter (as shown in figure below), the temperature rises from 23.6°C to 47.4°C. Calculate ΔH in kJ/mol NaOH, for the solution process
NaOH(s) → Na+(aq) + OH−(aq)
Assume that the specific heat of the solution is the same as that of pure water.Only thing I really need help on this one is the start of it. It shows 9.55g of NaOH dissolves in 100g of H2O. I forgot how to convert or whatever it is called to calculate the actual mass I will be using for the problem.
Thanks alot guys. I apperciate any help possible. I have more but thats enough for today