Question

Aqueous copper(II) nitrate reacts with aqueous sodium sulfide to produce aqueous sodium nitrate and copper(II) sulfide as a precipitate. In this reaction 469 grams of copper(II) nitrate were combined with 156 grams of sodium sulfide to produce 272 grams of sodium nitrate.

Answer 1

Yield of reaction = 80%

Further explanation

Reaction

Cu(NO₃)₂ (aq) + Na₂S (aq) ⇒ 2 NaNO₃ (aq) + CuS (s)

mol Cu(NO₃)₂ :(MW 187,56 g/mol)

$\tt \dfrac{469}{187.56}=2.5$

mol Na₂S :(MW 78,0452 g/mol)

$\tt \dfrac{156}{78.0452}=2$

 Limiting reactant⇒Na₂S( 2 < 2.5)

mol of NaNO₃ (MW = 84,9947 g/mol)

$\tt 2\times 2=4$

mass  NaNO₃ (theoretical)

$\tt 4\times 84.9947=339.979~g$

• yield

$\tt \dfrac{272}{339.979}=0.8\rightarrow=80\%$