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3 years ago

What is the ph of pure water at 40.0°c if the kw at this temperature is 2.92 × 10-14?

Chemistry

1 answer:

olganol [36]3 years ago

5 0

Answer: pH = 6.77

Explanation:

1) Chemical equilibrium

2 H₂O (l) ⇄ H₃O⁺ (aq) + OH⁻ (aq)

2) Equilibrium constant, Kw

Kw = [H₃O⁺] × [OH⁻]

By stoichiometry [H₃O⁺] = [OH⁻]. Call it x

Kw = x²

x² = 2.92 × 10⁻¹⁴ M²

x = √ (2.92 × 10⁻¹⁴) = 1.709 × 10⁻⁷ M = [H₃O⁺]

3) pH

pH = - log [H₃O⁺] = - log (1.709 × 10⁻⁷) = 6.77

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The heat required to raise the temperature has been expressed as:

$\rm Heat=mass\;\times\;specific\;heat\;\times\;Change\;in\;temperature$

<h3>Computation for the heat energy required</h3>

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Learn more about specific heat, here:

brainly.com/question/2094845

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