# Need help with homeworkWatch

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#1
When 50 grams each of 1.0 M HCL and 1.0 M NaOH are mixed, the enthalpy of reaction is determined to be -2.85 kj

1. Write a balance chemical reaction.
- HCL + NaOH---> NaCL + H20

2. Determine the number of moles of HCL and NaOH that reacted.
- Number of HCL that reacted-- 1.4 mol HCL
- Number of NaOH that reacted-- 1.25 mol NaOH

3. How many moles of water were generated.
- 1.25 mol of water

4. Calculate kJ/ mol of H20 for this reaction.
?? Not sure

This is my attempt at the problems, I'm just having a tough time. Any help with this problem and explanation would be appreciated. And let me know if my answers are right so far! Thank you
0
5 years ago
#2
(Original post by EricRivers)
When 50 grams each of 1.0 M HCL and 1.0 M NaOH are mixed, the enthalpy of reaction is determined to be -2.85 kj

1. Write a balance chemical reaction.
- HCL + NaOH---> NaCL + H20
This is correct(apart from the use of upper case letters in chlorine and no subscripts when using numbers)

2. Determine the number of moles of HCL and NaOH that reacted.
- Number of HCL that reacted-- 1.4 mol HCL
- Number of NaOH that reacted-- 1.25 mol NaOH
This is not correct. You have used the wrong formula. You are told that you have 50g (=50ml) of solution.

Moles = molarity x volume in litres.

3. How many moles of water were generated.
- 1.25 mol of water

4. Calculate kJ/ mol of H20 for this reaction.
?? Not sure

This is my attempt at the problems, I'm just having a tough time. Any help with this problem and explanation would be appreciated. And let me know if my answers are right so far! Thank you
0
#3
(Original post by charco)
This is correct(apart from the use of upper case letters in chlorine and no subscripts when using numbers)

This is not correct. You have used the wrong formula. You are told that you have 50g (=50ml) of solution.

Moles = molarity x volume in litres.
So would it be 0.050 mol of HCl and 0.050 mol of NaOH?? that means moles of water is 0.050 as well?
0
5 years ago
#4
(Original post by EricRivers)
So would it be 0.050 mol of HCl and 0.050 mol of NaOH?? that means moles of water is 0.050 as well?
correct
0
#5
(Original post by charco)
correct
So would that make question 4.... 57kj/mol??
0
5 years ago
#6
(Original post by EricRivers)
So would that make question 4.... 57kj/mol??
numerically correct, although as energy is released the value should be negative ...
0
#7
(Original post by charco)
numerically correct, although as energy is released the value should be negative ...
oops punched it in my calculator wrong, thank you for the help!!
0
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