# chemistry

posted by .

Ok, I really need to know how to work problems like these so could someone please show me how to set it up?! Given this data:
1. C(graphite) + O2(g) produces CO2(g), delta H = -393.5 kJ
2. H2(g) + 1/2 O2(g) produces H2O(l), delta H = -285.8 kJ
3. Ch3OH(l) + 3/2 O2(g) produces Co2(g) + 2H2O(l), delta H = -726.4 kJ
Given these calculate the enthalpy change for:

• chemistry -

Use equation 1 as is. (delta H as is)
Add 2x equation 2 (and 2x delta H).
Reverse equation 3 and add to the other two (change the sign on delta H).
Then added the equations as noted and confirm you obtain the desired equation; finally, add the delta Hs (with changes as noted).

## Similar Questions

1. ### chemistry

please assist me with this themochemistry question Given the following data CaCO3 (s)>>>>>>CaO (s) + CO2(g) (g) Delta H = -178.1 kj C (s) + O2>>>>>>CO2 (g) Delta H = -393.5 kj Calculate enthalpy …
2. ### Chemistry

Data: C(graphite) + O2(g) forms CO2 (ga) Delta H = -393.5kJ H2(g) + 1/2O2(g) forms H2O(l)Delta H = 285.8kJ. CH3OH(l) + 3/2O2(g)forms CO2(g) + 2H2O(l)Delta H = -726.4 Using data above, calculate the enthalpy change for the raction below …
3. ### Chemistry

Given the following heats of combustion. CH3OH(l) + 3/2 O2(g) CO2(g) + 2 H2O(l) ΔH°rxn = -726.4 kJ C(graphite) + O2(g) CO2(g) ΔH°rxn = -393.5 kJ H2(g) + 1/2 O2(g) H2O(l) ΔH°rxn = -285.8 kJ Calculate the enthalpy of …
4. ### chemistry

CH4 + 2O2 ---> CO2 + 2H2O Delta H H2O= -285.8 kJ/mole Delta H CO2= -393.3 kJ/mole What is the standard heat of formation of methane, Delta H CH4, as calculated from the data above
5. ### Chemistry II

Saw this one already answered, but did not understand at all... Calculate the delta Hf of C6H12O6 (s) from the following data: Delta H combustion= -2816 kj/mol delta Hf of Co2 = -393.5 kj/mol delta Hf= of H2 O= -285.9kj/mol
6. ### Chemistry

The reaction through which carbon changes from graphite to diamond form is represented by the equation C(graphite) ---> C(diamond) delta H: ?
7. ### Chem

The reaction through which carbon changes from graphite to diamond form is represented by the equation C(graphite) ---> C(diamond) delta H: ?