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3 years ago

If kb for nx3 is 4.0×10−6, what is the poh of a 0.175 m aqueous solution of nx3?

Chemistry

1 answer:

Elena-2011 [213]3 years ago

7 0

<h3><u>Answer;</u></h3>

pOH = 3.08

<h3><u>Explanation;</u></h3>

NX3 + H2O <----> NHX3+ + OH-

Kb = 4.0 x 10^-6

Kb = c(NH₄⁺) · c(OH⁻) ÷ c(NH₃).

c(NH₄⁺) = c(OH⁻) = x.

x² = Kb · c(NH₃)

x² = 4.0 × 10⁻⁶ × 0.175 = 7.0 × 10⁻⁷.

x = c(OH⁻) = √(7.0 × 10⁻⁷)

= 8.367 × 10⁻⁴

pOH = -log(c(OH⁻))

=- log ( 8.367 × 10⁻⁴)

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Answer:

$\frac{[magenta\ phenolphthalein]}{[colorless\ phenolphthalein]}=31.62$

Explanation:

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3 years ago

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3 years ago

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Answer : The given compound belongs to ether and alcohol.

Explanation :

The chemical formula of the given compound is, $C_5H_{12}O_2$

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3 years ago

Researchers used a combustion method to analyze a compound used as an antiknock additive in gasoline. A 9.394 mg sample of the c

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Answer:

The percent composition of the compound is 90.5 % C and 9.5 % H

Explanation:

Step 1: Data given

Mass of compound = 9.394 mg

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Mass of H2O yielded = 7.977 mg

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Molar mass of H2O = 18.02 g/mol

Step 2: Calculate moles CO2

moles of CO2 = (0.031154 g / 44.01 g/mol) = 7.08 * 10^-4 mol CO2

Step 3: Calculate moles C

moles of C = moles of CO2 * (1 mol C / 1 mol CO2)

moles of C = 7.08 * 10^-4 mol

Step 4: Calculate moles H2O

moles of H2O = (0.007977 g / 18.02 g/mol) = 4.43 * 10^-4 mol H2O

Step 5: Calculate moles of H

moles of H = moles of H2O * (2 mol H / 1 mol H2O)

moles of H = 4.43* 10^-4 *2 = 8.86 * 10^-4 mol H

Step 6: Calculate mass of C

mass C = moles C * molar mass C

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mass C = 0.0085 grams

Step 7: Calculate mass of H

mass H = moles H * molar mass H

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mass H = 0.000894 grams

Step 8: Calculate total mass of compound =

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Step 9: Calculate the percent composition:

% C = (8.50 mg / 9.394 mg) x 100 = 90.5%

% H = (0.894 mg / 9.394 mg) x 100 = 9.5%

The percent composition of the compound is 90.5 % C and 9.5 % H

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