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When 1.175 g of copper reacts with chlorine gas 6.725 g of copper chloride is formed - Leaving Cert Chemistry - Question h - 2005
Question h
When 1.175 g of copper reacts with chlorine gas 6.725 g of copper chloride is formed. Find by calculation the empirical formula of the chloride.
Worked Solution & Example Answer:When 1.175 g of copper reacts with chlorine gas 6.725 g of copper chloride is formed - Leaving Cert Chemistry - Question h - 2005
Step 1
Calculate the moles of Copper (Cu)
Answer
First, we need to calculate the number of moles of copper used in the reaction. The molar mass of copper (Cu) is approximately 63.5 g/mol.
Moles of Cu = ( \frac{\text{mass of Cu}}{\text{molar mass of Cu}} = \frac{1.175 , ext{g}}{63.5 , \text{g/mol}} = 0.0185 : \text{mol} )
Step 2
Calculate the moles of Chlorine (Cl)
Answer
Next, we calculate the mass of chlorine in the copper chloride. The mass of chlorine can be found by subtracting the mass of copper from the total mass of copper chloride.
Mass of Cl = 6.725 g - 1.175 g = 5.550 g
The molar mass of chlorine is approximately 35.5 g/mol.
Moles of Cl = ( \frac{\text{mass of Cl}}{\text{molar mass of Cl}} = \frac{5.550 , ext{g}}{35.5 , \text{g/mol}} = 0.1563 : \text{mol} )
Step 3
Determine the mole ratio of Cu to Cl
Answer
To find the empirical formula, we now need the simplest ratio of moles of Cu to moles of Cl.
(\text{Ratio Cu: Cl} = \frac{0.0185}{0.0185} : \frac{0.1563}{0.0185} = 1 : 8.45 )
After simplifying, the ratio can be approximated to 1 : 8. This suggests an empirical formula of (\text{CuCl}_2).