Part 1
a) 4.2 x 10⁻⁵ mole
b) 8.5 moles
c) 0.0083 moles
d) 0.505 moles
e) 0.0034
Part 2
a) 1103 g
b) 787 g
c) 678 g
d) 202 g
e) 147 g
Explanation:
Part 1
Calculation of number of moles for the following
a) 0.0082 g of Gold
Data given:
mass of Gold (Au) = 0.0082 g
no. of moles (Au) = ?
Formula to be Used
No. of moles = mass in grams / molar mass
Molar mass of Au = 197 g/mol
Put values in the formula
No. of moles = 0.0082 g / 197 g/mol
No. of moles = 4.2 x 10⁻⁵
No. of moles of (Au) = 4.2 x 10⁻⁵moles
b) 812 g of Molybdenum
Data given:
mass of Molybdenum (Mo) = 812 g
no. of moles (Mo) = ?
Formula to be Used
No. of moles = mass in grams / molar mass
Molar mass of Mo = 96 g/mol
Put values in the formula
No. of moles = 812 g / 96 g/mol
No. of moles = 8.5
No. of moles of (Mo) = 8.5 moles
c) 2.02 g of Americium
Data given:
mass of Americium (Am) = 2.02 g
no. of moles (Am) = ?
Formula to be Used
No. of moles = mass in grams / molar mass
Molar mass of Am = 243 g/mol
Put values in the formula
No. of moles = 2.02 g / 243 g/mol
No. of moles = 0.0083
No. of moles of (Am) =
d) 10.09 g of Neon
Data given:
mass of Neon (Ne) = 10.09 g
no. of moles (Ne) = ?
Formula to be Used
No. of moles = mass in grams / molar mass
Molar mass of Ne = 20 g/mol
Put values in the formula
No. of moles = 10.09 g / 20 g/mol
No. of moles = 0.505
No. of moles of (Ne) = 0.505 moles
e) 0.705 g of Bismuth
Data given:
mass of Bismuth (Bi) = 0.705 g
no. of moles (Bi) = ?
Formula to be Used
No. of moles = mass in grams / molar mass
Molar mass of Bi = 209 g/mol
Put values in the formula
No. of moles = 0.705 g / 209 g/mol
No. of moles = 0.0034
No. of moles of (Bi) = 0.505 moles
Part 2
Calculation of number of grams for the following
a) 5.6 mole of Au
Data given:
moles of Gold (Au) = 5.6 mol
mass of Au = ?
Formula to be Used
mass in grams = No. of moles x molar mass
Molar mass of Au = 197 g/mol
Put values in the formula
mass in grams = 5.6 mol x 197 g/mol
mass in grams = 1103 g
mass in grams of (Au) = 1103 g
b) 8.2 mole of Mo
Data given:
moles of Mo = 8.2 mol
mass of Mo = ?
Formula to be Used
mass in grams = No. of moles x molar mass
Molar mass of Mo = 96 g/mol
Put values in the formula
mass in grams = 8.2 mol x 96 g/mol
mass in grams = 787 g
mass in grams of (Mo) = 787 g
c) 2.79 mole of Am
Data given:
moles of Am = 2.79 mol
mass of Am = ?
Formula to be Used
mass in grams = No. of moles x molar mass
Molar mass of Am = 243 g/mol
Put values in the formula
mass in grams = 2.79 mol x 243 g/mol
mass in grams = 678 g
mass in grams of (Am) = 678 g
d) 10.09 mole of Ne
Data given:
moles of Ne = 10.09 mol
mass of Ne = ?
Formula to be Used
mass in grams = No. of moles x molar mass
Molar mass of Ne = 20 g/mol
Put values in the formula
mass in grams = 10.09 mol x 20 g/mol
mass in grams = 202 g
mass in grams of (Ne) = 202 g
e) 0.705 mole of Bi
Data given:
moles of Bi = 0.705 mol
mass of Bi = ?
Formula to be Used
mass in grams = No. of moles x molar mass
Molar mass of Bi = 209 g/mol
Put values in the formula
mass in grams = 0.705 mol x 209 g/mol
mass in grams = 147 g
mass in grams of (Bi) = 147 g
