Question

rt APart complete Calculate [H+] for [OH−]=4.1×10−4 M. Express your answer using two significant figures. [H+][ H + ] = 2.4×10−11 M Previous Answers Correct The formula for the ion-product constant of water, Kw, is [OH−][H+]= 1×10−14. When rearranged to solve for [H+], it becomes [H+]===Kw[OH−]1.0×10−144.1×10−42.4×10−11M Part BPart complete Calculate [H+] for [OH−]=8.5×10−9 M. Express your answer using two significant figures. [H+][ H + ] = 1.2×10−6 M Previous Answers Correct Part CPart complete Calculate [H+] for a solution in which [OH−] is 100 times greater than [H+]. Express your answer using two significant figures. [H+][ H + ] = 1.0×10−8 M Previous Answers Correct Since the [OH−] is 100 times greater than the [H+], this expression, [OH−]=100[H+], can be substituted into the ion-product constant expression: Kw==[H+]×100[H+]100[H+]2 Rearranging the equation to solve for [H+]: [H+]===(Kw100)1/2(1.0×10−14100)1/21.0×10−8M Part D Indicate whether the solution is acidic, basic, or neutral.

Answer 1

Answer:

A: [H⁺] = 2.4 × 10⁻¹¹ M

B: [H⁺] = 1.2 × 10⁻⁶ M

C: [H⁺] =  1.0 × 10⁻⁸ M

D: A and C are basic and B is acid.

Explanation:

Part A: Calculate [H⁺] for [OH⁻] = 4.1×10⁻⁴ M.

We know the ion-product of water Kw is:

Kw = 1.0 × 10⁻¹⁴ = [H⁺].[OH⁻]

Then,

$[H^{+} ]=\frac{K_{w}}{[OH^{-} ]} =\frac{1.0\times 10^{-14} }{4.1\times 10^{-4}} =2.4\times10^{-11} M$

Part B: Calculate [H⁺] for [OH⁻] = 8.5×10⁻⁹ M.

Kw = 1.0 × 10⁻¹⁴ = [H⁺].[OH⁻]

$[H^{+} ]=\frac{K_{w}}{[OH^{-} ]} =\frac{1.0\times 10^{-14} }{8.5\times 10^{-9}} =1.2\times10^{-6} M$

Part C: Calculate [H⁺] for a solution in which [OH⁻] is 100 times greater than [H⁺].

We know that [OH⁻] = 100 . [H⁺]. If we replace this in the ion-product of water:

Kw = 1.0 × 10⁻¹⁴ = [H⁺].[OH⁻]

1.0 × 10⁻¹⁴ = [H⁺]. 100. [H⁺]

1.0 × 10⁻¹⁴ = 100 . [H⁺]²

1.0 × 10⁻¹⁶ = [H⁺]²

[H⁺] = √1.0 × 10⁻¹⁶ = 1.0 × 10⁻⁸ M

Part D: Indicate whether the solution is acidic, basic, or neutral.

A solution is acid when [H⁺] > 10⁻⁷ M, basic when [H⁺] < 10⁻⁷ M and neutral when [H⁺] = 10⁻⁷M. So A and C are basic and B is acid.