Calculate the number of moles of [tex]CuCl_2 \[.\] 2H_2O[/tex] in a mass of 2.42 g to 3 significant figures.
Answer (2)
To find the number of moles of CuCl₂ · 2H₂O in 2.42 g, first calculate the molar mass, which is 170.48 g/mol. Then, using the formula for moles, the result is approximately 0.0142 moles, which rounds to 0.0142 moles at three significant figures.
;
To calculate the number of moles of CuCl_2 \cdot 2H_2O in a mass of 2.42 g, we need to use the formula for moles:
moles = molar mass mass
First, let's determine the molar mass of CuCl_2 \cdot 2H_2O:
Copper (Cu): The atomic mass is approximately 63.55 g/mol.
Chlorine (Cl): The atomic mass is approximately 35.45 g/mol. Since there are two chlorine atoms, we calculate the mass as: 2 × 35.45 = 70.90 g/mol
Water (H_2O): The molar mass of water is approximately 18.02 g/mol. Since there are two water molecules, we calculate the mass as: 2 × 18.02 = 36.04 g/mol
Adding these values together gives the molar mass of CuCl_2 \cdot 2H_2O: 63.55 + 70.90 + 36.04 = 170.49 g/mol
Now, we find the number of moles in 2.42 grams of CuCl_2 \cdot 2H_2O: moles = 170.49 g/mol 2.42 g ≈ 0.0142 moles
Therefore, the number of moles of CuCl_2 \cdot 2H_2O in 2.42 g is approximately 0.0142 moles.
