# Chemistry

When 0.250 mol of CH4(g) reacts with excess Cl2(g) at constant pressure according to the chemical equation shown below, 177 kJ of heat are released. Calculate the value of Delta H for this reaction, as written.

2CH4(g)+3Cl2(g)-->2CHCl3(l)+3H2(g)

delta H=?

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1. If 1/4 mole releases 177 kJ, then 1 mole will release 4x that and 2 moles will release 8x that. Check my thinking.

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2. +1420kJ?

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3. I get 1416 kJ. If you rounded your answer because of significant figures, showing it as 1420 won't do it. Most texts recommend writing it as 1.42 x 10^3 kJ.

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4. hhmm would it be 4x that amount and not 8? im confused

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5. moles = grams/molar mass
0.25 = g/16 and grams = 0.25 x 16 = 4 grams.
The equation as written is 2 moles CH4 so that is 16 x 2 = 32 grams.
177 kJ (for the reaction for the 4 grams) x (32/4) = ??

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6. i guess the teacher put a bad answer bank none of the answer are 1416 but i get what you are saying i will bring this up to him thanx

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7. Try 1.42 x 10^3 kJ and let me know.

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