menu
QAmmunity.org
Login
Register
My account
Edit my Profile
Private messages
My favorites
Ask a Question
Questions
Unanswered
Tags
Categories
Ask a Question
Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2. From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.
asked
Sep 28, 2017
228k
views
1
vote
Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2.
From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s):
CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.2kJ
ΔH∘f = kj?
Chemistry
college
Rum
asked
by
Rum
8.0k
points
answer
comment
share this
share
0 Comments
Please
log in
or
register
to add a comment.
Please
log in
or
register
to answer this question.
1
Answer
2
votes
The answer is -60.57. With appropriate sig figs it becomes -60.6 KJ.
I think you were on the right track. However you need to multiply H2O by its coefficient from the balanced equation. Then you also need to keep in mind the signs.
Maybe it's easier if I write what I did out:
2H2O > 2H2 +O2...............-H= 2* -285.83
Ca + O2 + H2 > Ca(OH)2....H= -986.2
2C + H2 > C2H2.................H= 226.77
The above H's stand for standard enthalpy of formations. These can be found in textbook appendix. Notice the negative infront of the enthalpy (H) for H2O. This is to remind me/you that the heat lost is gained in the rxn.
So then you add them up. 226.77 - 986.2 + (2*285.83) = -187.77
Add back the total enthalpy that is given in the question -187.77+127.2 = -60.57
If signs cross you up find a way to remember that works for you.
Juan Delgado
answered
Oct 4, 2017
by
Juan Delgado
8.1k
points
ask related question
comment
share this
0 Comments
Please
log in
or
register
to add a comment.
← Prev Question
Next Question →
Related questions
asked
Oct 22, 2017
217k
views
Calcium carbide (CaC2) reacts with water to form acetylene (C2H2) and Ca(OH)2. From the following enthalpy of reaction data and data in Appendix C, calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g)ΔH∘=−127.
Robert Gowland
asked
Oct 22, 2017
by
Robert Gowland
7.9k
points
Chemistry
college
1
answer
2
votes
217k
views
asked
Apr 4, 2017
152k
views
Calculate ΔH∘f for CaC2(s): CaC2(s)+2H2O(l)→Ca(OH)2(s)+C2H2(g) ΔH∘=−127.2kJ
Hong Ning
asked
Apr 4, 2017
by
Hong Ning
8.6k
points
Chemistry
college
1
answer
2
votes
152k
views
asked
Jul 14, 2021
20.7k
views
Calcium carbide reacts with water to produce acetylene gas according to the following equation: CaC2(s) + 2H2O(l)C2H2(g) + Ca(OH)2(aq) The product gas, C2H2, is collected over water at a temperature of
WebChemist
asked
Jul 14, 2021
by
WebChemist
7.9k
points
Chemistry
college
1
answer
1
vote
20.7k
views
Ask a Question
Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.
9.5m
questions
12.2m
answers
Other Questions
How do you balance __H2SO4 + __B(OH)3 --> __B2(SO4)3 + __H2O
Can someone complete the chemical reactions, or write which one do not occur, and provide tehir types? *c2h4+h2o *c3h8 + hcl *c2h2+br2 *c4h10+br2 *c3h6+br2
As an object’s temperature increases, the ____________________ at which it radiates energy increases.
What is the evidence of a chemical reaction when the fireworks go off
Which of the following statements does not describe a physical property of a piece of chalk A. Chalk is solid B.chalk can be broken into pieces C. Chalk is white D. Chalk will bubble in vinegar
Twitter
WhatsApp
Facebook
Reddit
LinkedIn
Email
Link Copied!
Copy
Search QAmmunity.org