Question

Which statement about a compound on this pH scale explains why it is the strongest acid?

Missing Metadata



A.
RbOH is a strong acid because it has the greatest pH.


B.
HCl is a strong acid because its pH is the lowest number on the pH scale.


C.


HIO3 is a strong acid because its pH is closest to 7.


D.
HBr is a strong acid because its pH is less than 7.

Answer 1

b. HCl

Answer 2

@aaronq

Answer 3

The question is weirdly worded because pH is dependent on the concentration of any acid.
The more acid present in a solution, the more acidic the solution is (lower pH).

HBr is a stronger acid than HCl (because the bond holding them together is weaker), but all in all they're both very strong acids. They must've had a lower concentration of HBr than HCl.

So the answer above "HCl" is correct simply because on the pH scale the lower you go (closer to zero or even negative) the more acidic a solution is. A more acidic solution simply means that there is a larger \([H_3O^+]\).

pH and \([H_3O^+]\) have a logarithmic relationship: \(pH=-log[H_3O^+]\)

this just means that from pH 1 to pH the number of \([H_3O^+]\) decreases by a factor of 10.

Answer 4

@aaronq plz tell me, that why the pH of HCl is less than HBr.

Answer 5

pH is not a property of an acid nor a base, but of a solution. It's a measure of the concentration of hydronium ions, \(H_3O^+\), in a solution.

pH=1 for HCl \([H_3O^+]=10^{-1}=0.1~M\)
pH=3.5 for HBr \([H_3O^+]=10^{-3.5}=3.16*10^{-4}~M\)

Because acids are monoprotic (have only one acidic proton) and their dissociation ~100%: \([HA]=[H_3O^+]\).

\([HCl]=0.1~M\)
\([HBr]=3.16*10^{-4}~M\)

So because they used much less solute in the HBr solution, the pH of the HCl solution is lower.

Answer 6

thanks bro...

Answer 7

no problem