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3 years ago

The weak acid HA is 2% ionized (dissociated) in a 0.20 M solution.

Chemistry

1 answer:

nekit [7.7K]3 years ago

7 0

Answer:

1. Ka = 8.16x10⁻⁵

2. pH = 2.40

Explanation:

1. The dissociation of a weak acid in water occurs as follows:

HA ⇄ H⁺ + A⁻

Ka = [H⁺] [A⁻] / [HA]

As 2% of the 0.20M solution is dissociated:

[H⁺] = [A⁻] = 0.20M * 2% = 0.004M -As H⁺ and A⁻ comes from the same reaction, their concentrations are the same

[HA] = 0.20M * 98% = 0.196M

Ka = (0.004)² / (0.196M) = 8.16x10⁻⁵

2. pH = -log [H⁺] = -log [0.004M]

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Arte-miy333 [17]

Answer:

7.6 days

Explanation:

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Thus,

$\frac{1}{4} =1(\frac{1}{2} )^\frac{t}{3.8}$

We can write is as,

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3 years ago

The half-life of a first-order reaction is 13 min. If the initial concentration of reactant is 0.085 M, how long would it take u

olasank [31]

Answer: It will take 8.2 minutes until the concentration decreases to 0.055 M

Explanation:

The time after which 99.9% reactions gets completed is 40 minutes

Explanation:

Expression for rate law for first order kinetics is given by:

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k = rate constant

t = age of sample

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a) for completion of half life:

Half life is the amount of time taken by a radioactive material to decay to half of its original value.

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3 years ago

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Answer:

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2 years ago

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3 years ago

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frutty [35]

We are going to use this formula:

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3 years ago