Chemistry (pH and pOH) #3

Chemistry Level 1

Using $\log 2 = 0.3$ , $\log 10 = 1$ and $\log 3 = 0.45$ , classify the 3 solutions below in A ( pH < 7), B ( pH > 7) or C (pH = 7).

Solution I: $[OH^{-}] = 2 \times 10^{-3}$

Solution II: $[OH^{-}] = 8 \times 10^{-9}$

Solution III: $[H^{+}] = 10^{-7}$

I B, II B, III C I A, II B, III C I B, II A, III C I A, II A, III C

1 solution

Abyoso Hapsoro
May 5, 2015

Let's try to figure this without the need of calculating, ${Solution I}$ $pOH = 3 - log 2$ $pH = 11 + log 2$ Therefore, Solution 1 is B, or pH higher than 7 ${Solution II}$ $pOH = 9 - log 8$ $pH = 5 + log 8$ Since $log 8 < 1$ , Solution 2 is A, or pH lower than 7 $Solution 3$ $pH = 7$ Therefore, Solution 3 is C, or pH equal to 7

Good problem, but the approach is confusing, regards!

Elias Caballero - 1 month ago

Chemistry (pH and pOH) #3

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