tbr test 3 physical sciences q 31

[2010premed]

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The highest final temperature after reaction would be observed in which of the following mixtures?

A. 100 mL 1.0 M KOH + 50 mL 2.0 M HCl
B. 100 mL 2.0 M KOH + 100 mL 2.0 M HCl
C. 100 mL 1.0 M KOH + 300 mL 1.0 M HCl
D. 100 mL 1.0 M KOH + 200 mL 0.5 M HCl

Ans: B

I picked B just b/c it was the most, but I don't understand the idea/chemistry behind this question. The explanation says that "The highest final temperature results from the greatest release of heat per volume of water"

What do they mean by this? I didn't think it had anything to do with water...

 

[Pons Asinorum]

I would ask the mods if they could start you your own subforum inside MCAT Q&A. Might be easier that way to get an explanation for every question on the TBR FL's answered for you. Just saying.

The highest final temperature after reaction would be observed in which of the following mixtures?

A. 100 mL 1.0 M KOH + 50 mL 2.0 M HCl
B. 100 mL 2.0 M KOH + 100 mL 2.0 M HCl
C. 100 mL 1.0 M KOH + 300 mL 1.0 M HCl
D. 100 mL 1.0 M KOH + 200 mL 0.5 M HCl

Ans: B

I picked B just b/c it was the most, but I don't understand the idea/chemistry behind this question. The explanation says that "The highest final temperature results from the greatest release of heat per volume of water"

What do they mean by this? I didn't think it had anything to do with water...

 

[Pons Asinorum]

And to answer this question, heat is being generated by the formation of water. The units for heat of formation of water are kJ/mol; which one of these reactions forms the highest number of moles of water?

The highest final temperature after reaction would be observed in which of the following mixtures?

A. 100 mL 1.0 M KOH + 50 mL 2.0 M HCl
B. 100 mL 2.0 M KOH + 100 mL 2.0 M HCl
C. 100 mL 1.0 M KOH + 300 mL 1.0 M HCl
D. 100 mL 1.0 M KOH + 200 mL 0.5 M HCl

Ans: B

I picked B just b/c it was the most, but I don't understand the idea/chemistry behind this question. The explanation says that "The highest final temperature results from the greatest release of heat per volume of water"

What do they mean by this? I didn't think it had anything to do with water...