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stiv31 [10]
3 years ago
5

How many oxygen atoms are there in 6.00 g of sodium dichromate, na2cr2o7?

Chemistry
1 answer:
mel-nik [20]3 years ago
6 0
Answer is: there are 9,7·10²² atoms of oxygen.
m(Na₂Cr₂O₇) = 6,00 g.
n(Na₂Cr₂O₇) = m(Na₂Cr₂O₇) ÷ M(Na₂Cr₂O₇).
n(Na₂Cr₂O₇) = 6 g ÷ 262 g/mol.
n(Na₂Cr₂O₇) = 0,023 mol.
n(Na₂Cr₂O₇) : n(O) = 1 : 7.
n(O) = 7 · 0,023 mol.
n(O) = 0,161 mol.
N(O) = 0,161 mol · 6,022·10²³ 1/mol.
N(O) = 9,7·10²².
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Answer:

pH = 3.65    

Explanation:

given data

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to find out

What is the pH

solution

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5 0
4 years ago
Read 2 more answers
A 1.450 g sample of an unknown organic compound , X, is dissolved in 15.0 g of toluene
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Answer:

Molecular weight of the compound = 372.13 g/mol

Explanation:

Depression in freezing point is related with molality of the solution as:

\Delta T_f = K_f \times m

Where,

\Delta T_f = Depression in freezing point

K_f = Molal depression constant

m = Molality

\Delta T_f = K_f \times m

1.33 = 5.12 \times m

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0.26 = \frac{Mole\ of\ compound}{0.015}

Moles of compound = 0.015 × 0.26 = 0.00389 mol

Mol = \frac{Mass\ in\ g}{Molecular\ weight}

Mass of the compound = 1.450 g

Molecular\ weight = \frac{Mass\ in\ g}{Moles}

Molecular weight = \frac{1.450}{0.00389} = 372.13\ g/mol

4 0
3 years ago
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