The mineral enargite is 48.41% cu, 19.02% as, and 32.57% s by mass. what is the empirical formula of enargite?

1 answer:

4 0

Answer is: <span>the empirical formula of enargite is Cu</span>₃AsS₄.<span>
If we use 100 grams of enargite:
n(Cu) = 48,41 g </span>÷ 63.55 g/mol.
n(Cu) = 0.761 mol.
n(As) = 19.02 g ÷ 74.92 g/mol.
n(As) = 0.254 mol.
n(S) = 32.57 g ÷ 32.065 g/mol.
n(S) = 1.016 mol.
n(Cu) : n(As) : n(S) = 0.761 mol : 0.254 mol : 1.016 mol / 0.254.
n(Cu) : n(As) : n(S) = 3 mol : 1 mol : 4 mol.

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Answer:

$r=\frac{r(NO_{2})}{2} =\frac{r(O_{2})}{1/2}=\frac{r(N_{2}O_{5})}{1}$

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Let us consider the reaction:

2 NO₂ + 1/2 O₂ ⇄ N₂O₅

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The rate of disappearance of a reactant is equal to to the change in concentration of the reactant divided the change in time, with a negative sign so that the rate is always a positive variable.

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$r=\frac{r(NO_{2})}{2} =\frac{r(O_{2})}{1/2}=\frac{r(N_{2}O_{5})}{1}$

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Answer:

3. 76 g/ml^3

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