Posted by Daqa on Thursday, March 18, 2010 at 8:19pm.
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.
Chemistry - DrBob222, Thursday, March 18, 2010 at 8:22pm
If 1/4 mole releases 177 kJ, then 1 mole will release 4x that and 2 moles will release 8x that. Check my thinking.
Chemistry - Daqa, Thursday, March 18, 2010 at 8:27pm
Chemistry - DrBob222, Thursday, March 18, 2010 at 8:32pm
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.
Chemistry - Daqa, Thursday, March 18, 2010 at 8:43pm
hhmm would it be 4x that amount and not 8? im confused
Chemistry - DrBob222, Thursday, March 18, 2010 at 8:48pm
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) = ??
Chemistry - Daqa, Thursday, March 18, 2010 at 8:51pm
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
Chemistry - DrBob222, Thursday, March 18, 2010 at 9:35pm
Try 1.42 x 10^3 kJ and let me know.
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