Question

Plz answer correctly....The concentration of either the H+ ion or the OH − ion is given for four aqueous solutions at 298 K.?

For each solution, calculate [H+] or [OH − ]. State whether the solution is acidic, basic, or neutral.

(a) [H+] = 8.0 * 10^-13 M
[OH − ] =

(b) [OH − ] = 4.0 * 10^-7 M
[H+] =

(c) [OH − ] = 5.0 * 10^-3 M
[H+] =

(d) [H+] = 8.0 * 10^-5 M
[OH − ] =

Answer 1

Definitions needed:

pH = -log[H^+]

pOH = -log[OH^-]

pH + pOH = 14

[H^+]*[OH^-] = 10^-14

(a) [H+] = 3.0 10-13 M

[OH ‾ ] = _____ M

Acidic, Basic, or Neutral?

[H^+]*[OH^-] = 10^-14

[OH^-] = (10^-14)/[H^+]

[OH^-] = (10^-14)/(3.0 10-13 M) = 0.033 M

That's a high concentration of [OH^-], so the solution is basic

(b) [OH ‾ ] = 3.0 10-7 M

[H+] = ______M

Acidic, Basic, or Neutral?

[H^+]*[OH^-] = 10^-14

[H^+]* = (10^-14)/[OH^-]

[H^+]* = (10^-14)/(3.0 10-7 M) = 3.33 x 10^-8

That would be a slightly basic solution (pH just higher than 7).

Answer 2

Explanation :

Solution for part (a) :

Concentration of
`H^+` =
`8.0* 10^(-13)M`

As we know that,

`[H^+][OH^-]=10^(-14)`

Now put the value of concentration of hydrogen ion, we get concentration of hydroxide ion.

`(8.0* 10^(-13))* [OH^-]=10^(-14)`

`[OH^-]=1.25* 10^(-2)M`

From this we conclude that, the concentration of hydroxide ion is more than the hydrogen ion that means the solution is basic in nature.

Solution for part (b) :

Concentration of
`OH^-` =
`4.0* 10^(-7)M`

As we know that,

`[H^+][OH^-]=10^(-14)`

Now put the value of concentration of hydroxide ion, we get concentration of hydrogen ion.

`[H^+]* (4.0* 10^(-7))=10^(-14)`

`[H^+]=0.25* 10^(-7)M`

From this we conclude that, the concentration of hydrogen ion is more than the hydroxide ion that means the solution is acidic in nature.

Solution for part (c) :

Concentration of
`OH^-` =
`5.0* 10^(-3)M`

As we know that,

`[H^+][OH^-]=10^(-14)`

Now put the value of concentration of hydroxide ion, we get concentration of hydrogen ion.

`[H^+]* (3.0* 10^(-3))=10^(-14)`

`[H^+]=0.25* 10^(-7)M`

From this we conclude that, the concentration of hydroxide ion is more than the hydrogen ion that means the solution is basic in nature.

Solution for part (d) :

Concentration of
`H^+` =
`8.0* 10^(-5)M`

As we know that,

`[H^+][OH^-]=10^(-14)`

Now put the value of concentration of hydrogen ion, we get concentration of hydroxide ion.

`(8.0* 10^(-5))* [OH^-]=10^(-14)`

`[OH^-]=1.25* 10^(-2)M`

From this we conclude that, the concentration of hydrogen ion is more than the hydroxide ion that means the solution is acidic in nature.