
	Home


	Homework Help


	Answer Board


	Resources (Beta)

You Are Here:

Home > Answer Board > Chemistry > Topic: Heat of formation!!!!!!! please help

Member's Topic Headline:

Heat of formation!!!!!!! please help

Know the answer? Have a better solution? Share it.

Get Help Now.

View homework problems
explained for free!

Member Testimonials

Question:

When 10.00 ${\rm{ g}}$ of phosphorus is burned in ${\rm{O}}_2 (g{\rm{)}}$ to form ${\rm{P}}_4 {\rm{O}}_{10} (s)$ , enough heat is generated to raise the temperature of 2950 ${\rm{ g}}$ of water from 18.0 $^\circ {\rm C}$ to 38.0 $^\circ {\rm C}$ .Calculate the heat of formation of ${\rm{P}}_4 {\rm{O}}_{10} (s)$ under these conditions.

$\Delta H_f$ = Kj/mol

Bonus Point Alert! Earn +4 additional karma points for helping this annual member.

Answers:

CHEMNATION!

Oracle

Karma Points: 9,935

Date Posted: 6/6/2008 3:15:25 PM Status: Live

Asker's Rating: Lifesaver

Response:

Sorry, don't have a calculator but I will help you through the process.

(a)Water temp goes up so the sign on ΔH will be negative.

(b) The kJ part.....

q = mcΔT = 2950 g (4.18 J/g^oC)(38.0 - 18.0 (^oC))(1 kJ / 1000 J) = B

10.0 g P (1 mol P / 30.97 g P)( 1 mol P₄O₁₀/4 mol P) = C

Answer = - B/C

CR6's Comment:

Thanks !!!!!!

If you request assistance with 1 answer, I will provide 1 input. If you put in a project requesting assistance with x answers, I will in turn provide x inputs. In both scenarios, appropriate ratings are appreciated for every input.

PROBLEMS WITH CHEMICAL FORMULAS WILL BE ANSWERED FASTER IF PROPER CRAMSTER TOOLBAR FORMATS ARE USED.

By reading or posting messages on these forums, you are agreeing to the Answer Board's Terms of Service and Conduct (TSC).

Heat of formation!!!!!!! please help

Question:

Advertisement:

Answers: