中4chem (acids and bases0

[匿名]

2011-04-10 11:10 pm

1. Calculate the pH of each of the following solutions and indicate whether the solution is acidic or alkaline.
(a) [H+(aq)] = 1.8X10^-5M
(b) [H+(aq)] = 7.2X10^-9M
(c) stomach juice, [H+(aq)] = 0.02M

2. Calculate the molar H+(aq) ion concentration for
(a) a sulation of pH 5.2.
(b) a sulation of pH 8.4.
(c) rainwater of pH 3.68.

3. The instrument on the right can be used to compare the pH values of different aqueous solutions accurately.
(a) Name the instrument
(b) Suggest TWO advantages of using this kind of instrument

回答 (1)

★兒妹

2011-04-11 12:05 am

✔ 最佳答案

1. pH = -log[H+]

a) pH = -log(1.8X10^-5) = 4.74
pH<7, so it is acidic
b) pH = -log(7.2X10^-9) = 8.14
pH>7, so it is alkaline
c) pH = -log(0.02) = 1.70
pH<7, so it is acidic

2. [H+] = 10^(-pH)

a) [H+] = 10^(-5.2) = 6.31x10^-6 M
b) [H+] = 10^(-8.4) = 3.98x10^-9 M
c) [H+] = 10^(-3.68) = 2.09x10^-4 M

3. 因沒圖片的關係，只能估計答案

a) pH meter
b) It can give numerical value.
It is simple to use.

Hope the answers help you :)

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