# chemistry - hess's law (check + help)

posted by .

31. Carbon monoxide reacts with hydrogen gas to produce a mixture of methane, carbon dioxide, and water. (This mixture is known as substitute natural gas.)
4CO(g) + 8H2(g) → 3CH4(g) + CO2(g) + 2H2O(_)
Use the following thermochemical equations to determine the enthalpy change of the reaction.
C(graphite) + 2H2(g) → CH4(g) + 74.8 kJ
CO(g) + 12O2(g) → CO2(g) + 283.1 kJ
H2(g) + 12 O2(g) → H2O(g) + 241.8 kJ
C(graphite) + 12O2(g) → CO(g) + 110.5 kJ
H2O(l) + 44.0 kJ → H2O(g)

this is required to use the Hess's law, and the manipulation of the equations and mutiplying to get the coeeficients from the orginal question, however i am getting -641kJ...the answer is wrong..any suggestions of what to do..
below is my answer:
multiplied the 1st equation by 3
no change to the second equation
multiplied the 3rd equation by 2
mutiplied the 4th equation by 4 and flipped the equation
fifth equation multiplied by two and flipped

• chemistry - hess's law (check + help) -

It appears to me that the first equation x 3 gives 3C(graphite) and the fourth x 4 and reversed gives 4C(graphite) so those don't cancel. I stopped there.

## Similar Questions

1. ### Chemistry-Enthalpies of formation

"Synthesis gas" is a mixture of carbon monoxide and hydrogen that is used to synthesize a variety of organic compounds. One reaction for producing synthesis gas is 3CH4 + 2H2O + CO2 = 4CO + 8H2 Using enthalpies of formation, calculate …
2. ### Chemistry

A mole of methane reacts with 64g of oxygen at 1 atm, 425 K. There are two ways in which methane can react with oxygen. It can either form water vapor and carbon dioxide or water vapor and carbon monoxide. After reaction the final …
3. ### chemistry

Consider a 50 L tank which hold 20 g of hydrogen gas, 20 g of carbon dioxide gas, and 20 g of krypton gas, at a total pressure of 600 KPa. 1. which gas has the largest partial pressure?
4. ### Chemistry Balancing Equations

I really need help with balancing these equations: PLEASE HELP!! 1. Sodium Hydrogen Sulfite reacts with hydrochloric acid to produce sulfur dioxide gas, water and sodium chloride 2. Sodium nitrate reacts with hydrochloric acid to produce …
5. ### Chemistry Balancing Equations

Can you please tell me if these are correct?
6. ### Chemistry

Just having some trouble with this chemistry problem.. Thanks for help! Toxic carbon monoxide (CO) gas is produced when fossil fuels such as petroleum burn without enough oxygen. The CO can eventually be converted to CO2 in the atmosphere. …
7. ### Chemistry

An equilibrium mixture contains 0.250 mol of each of the products (carbon dioxide and hydrogen gas) and 0.200 mol of each of the reactants (carbon monoxide and water vapor) in a 1.00-L container. CO(g) + H2O(g) <-> CO2(g)+ H2(g) …
8. ### Chemistry

A 5.00 g mixture of methane (CH4) and ethane (C2H6) is combusted in oxygen gas to produce carbon dioxide and water. If 14.09 g of CO2 is produced, how many grams of methane was in the original 5.00 g mixture ?
9. ### Chemistry

Hydrogen gas is used for many purposes, including the hydrogenation of vegetable oils to make margarine. The most common industrial process for producing hydrogen is "steam reforming," in which methane gas, CH4, from natural gas reacts …
10. ### Chemistry

Hydrogen gas is used for many purposes, including the hydrogenation of vegetable oils to make margarine. The most common industrial process for producing hydrogen is "steam reforming," in which methane gas, CH4, from natural gas reacts …

More Similar Questions