mercury can be obtained by reacting mercury (...
mercury can be obtained by reacting mercury (ii) sulfide with calcium oxide. how many grams (rounded to two decimals places) of calcium oxide are needed to produce 36.0 g of hg?
Answer
# Answer:
12.44 g
# Explanation:
## Step1: Write the balanced chemical equation
$4HgS + 4CaO \rightarrow 4Hg + 3CaS+CaSO_{4}$
## Step2: Calculate the molar - mass of Hg and CaO
The molar mass of Hg ($M_{Hg}$) is approximately 200.59 g/mol, and the molar mass of CaO ($M_{CaO}$) is approximately 56.08 g/mol.
## Step3: Calculate the number of moles of Hg
$n_{Hg}=\frac{m_{Hg}}{M_{Hg}}=\frac{36.0\ g}{200.59\ g/mol}\approx0.1795\ mol$
## Step4: Determine the mole - ratio between CaO and Hg
From the balanced equation, the mole - ratio of CaO to Hg is 4:4 = 1:1. So, the number of moles of CaO needed ($n_{CaO}$) is equal to the number of moles of Hg produced, $n_{CaO}=n_{Hg}\approx0.1795\ mol$
## Step5: Calculate the mass of CaO
$m_{CaO}=n_{CaO}\times M_{CaO}=0.1795\ mol\times56.08\ g/mol\approx12.44\ g$