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# chemical equations and formulae Watch

1. hi i have a question that goes like so....

4.A student uses 50g of water and raises the temperature by 14°C (the specific heat capacity of water is 4.18J G). Calculating the enthalpy for this reaction. Show your calculations clearly.

14 x 50g x 4.18= 2926 J

5. The student used 0.755g of Pentane (C5H12) (C= atomic mass 12, H= 1)

a) How many moles of fuel were used?

0.755/ 72= 0.01 moles

b) Use the above to express your answer to question 4 in joules per mole.

can you help me out with 14. b) please!!!

p.s. it would also be really helpful to know the equations that i will need for my AS-Level; that would be really appreciated (most preferably in the form of triangle equations if you get what i mean, but it is no big deal if you cannot)

Thank you!!
2. (Original post by Sandhu22)
hi i have a question that goes like so....

4.A student uses 50g of water and raises the temperature by 14°C (the specific heat capacity of water is 4.18J G). Calculating the enthalpy for this reaction. Show your calculations clearly.

14 x 50g x 4.18= 2926 J

5. The student used 0.755g of Pentane (C5H12) (C= atomic mass 12, H= 1)

a) How many moles of fuel were used?

0.755/ 72= 0.01 moles

b) Use the above to express your answer to question 4 in joules per mole.

can you help me out with 14. b) please!!!

p.s. it would also be really helpful to know the equations that i will need for my AS-Level; that would be really appreciated (most preferably in the form of triangle equations if you get what i mean, but it is no big deal if you cannot)

Thank you!!

The moles used were 0.01 mol

Therefore Joules per mole = 2926/0.01 = 292,600 J mol-1
3. Thank You!!

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