Step-by-step explanation:
To calculate the number of moles of copper (II) sulfate crystals (CuSO4.5H2O) in 50g, we first need to find the molar mass of CuSO4.5H2O.
The molar mass of CuSO4 is:
Cu: 63.55 g/mol
S: 32.06 g/mol
O (4 atoms): 15.99 g/mol x 4 = 63.96 g/mol
H2O (5 molecules): 18.02 g/mol x 5 = 90.10 g/mol
Therefore, the molar mass of CuSO4.5H2O is:
Molar mass = (63.55 + 32.06 + 63.96 + 90.10) g/mol
= 249.67 g/mol
Next, we can use the formula:
number of moles = mass / molar mass
where mass is the given mass of CuSO4.5H2O, and molar mass is the value we just calculated.
Substituting the values, we get:
number of moles = 50 g / 249.67 g/mol
= 0.2002 mol (rounded to four significant figures)
Therefore, 50g of copper (II) sulfate crystals contain 0.2002 moles of CuSO4.5H2O