Acid & Akali

2007-06-11 9:24 am

1. Different volumes of 1 M sulphuric acid and 1M sodium hydroxide solution are mixed.
In which of the following combinations would the temperature rise be the greatest?

Volume of 1M sulphuric acid (aq)(cm3), Volume of 1M sodium hydroxide (aq)(cm3)
A. 10,35
B. 15,30
C. 20,25
D. 25,15

回答 (1)

Audrey Hepburn

2007-06-11 3:52 pm

✔ 最佳答案

H2SO4 (aq) + 2NaOH (aq) → Na2SO4 (aq) + 2H2O (l)

From the equation, molar ratio of H2SO4 : NaOH = 1 : 2

For A, H2SO4 is the limiting agent as 10 cm^3 of H2SO4 will react with 20 cm^3 NaOH.

For B, 15 cm^3 of H2SO4 will react with 30 cm^3 NaOH. The chemicals are fully utilized.

For C, 12.5 cm^3 of H2SO4 will react with 25 cm^3 of NaOH.

For D, 7.5 cm^3 of H2SO4 will react with 15 cm^3 of NaOH.

Obviously, in reaction B, there are more chemicals reacting with each other. So B will evolve most heat. And the temperature rise will be the greatest.

參考: Myself~~~

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