# Chemistry

posted by .

Ammonia (NH3) boils at -33oC; at this temperature it has a density of 0.81 g/cm3. The enthalpy of formation of NH3(g) is -46.2kj/mol, and the enthalpy of vaporization of NH3(l) is 23.2 kJ/mol. Calculate the enthalpy change when 1 L of liquid NH3 is burned in air to give N2(g) and H2O(g). How does this compare with ΔH for the complete combustion of 1 L of liquid methanol, CH3OH(l)? For CH3OH(l), the density at 25oC is 0.792 g/cm3, and ΔHof equals -239 kJ/mol.

• Chemistry -

For NH3, 0.81 g/cc x 1000 cc = 810 grams.
810g/17 = ? mols.

2NH3 + 3/2 O2 ==> N2 + 3H2O
dHrxn = (3*dHf H2O + 0) - (2*dH NH3) = ? kJ/mol
You need to add in 23.2 to that to go from liquid NH3 to burned NH3.
Then total dHrxn (including vaporization) x mols NH3 = kJ.

Do the same thing for CH3OH but I see no number for correction from liquid to gas.

## Similar Questions

1. ### Honors Chemistry

"How many grams of NH3 can be produced from the reaction of 28 g of N2 and 25 g of H2?
2. ### chemistry

Ammonia, NH3, is used as a refrigerant. At its boiling point of -33ºC, the enthalpy of vaporization of ammonia is 23.3 kJ/mol. How much heat is required to vaporize 125 g of ammonia at -33ºC?
3. ### Chemistry

Identify each enthalpy change by name and classify each change as exothermic or endothermic. a)1 mol C3H8 (l) ==> 1 mol C3H8 (g) b)1 mol Hg (l) ==> 1 mol Hg (s) c)1 mol NH3 (g) ==> 1 mol NH3 (l) d)1 mol NaCl(s) + 3.88kJ/mol …
4. ### college chemistry

How much heat is needed to convert 2.00 kg of liquid ammonia at -40.0 oC to its vapor at -11.0 oC?
5. ### ap chem

calculate the lattice enthalpy of potassium fluoride from the following data: enthalpy of formation of K(g): +89 kJ · mol−1 first ionization energy of K(g): +418 kJ · mol−1 enthalpy of formation of F(g): +79 kJ · mol−1 …
6. ### chemistry

what is the Molarity (M) of a 0.87m aqueous solution of ammonia, NH3?
7. ### Chemistry

calculate the enthalpy change for: (enthalpy of formation of aqueous sodium hydroxide is -469.60 kJ/mol. enthalpy of formation of liquid water is -285.8 kJ/mol) 2Na + 2H2O = 2 NaOH + H2
8. ### CHEM

Can you please check my work? I got -4.3KJ/mol If this is not right can you tell me what I am doing wrong?
9. ### chemistry

When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change …
10. ### chem

When NH3 is treated with oxygen gas, the products obtained are N2(g) and H2O(l). If standard enthalpies of formation at 298 K for NH3(g) and H2O(l) are –46.00 kJ/mol and –286.0 kJ/mol respectively, calculate the enthalpy change …

More Similar Questions