How many grams are in 4.5 moles of Li2O?

How many grams are in 4.5 moles of Li2O?

• A. 145.0 g Li2O
• B. 134.6 g Li2O
• C. 150.0 g Li2O
• D. 120.0 g Li2O

Answer: (B)

To determine the mass in grams of 4.5 moles of lithium oxide (Li2O), you first need to calculate the molar mass of Li2O. Lithium (Li) has an atomic mass of approximately 6.94 g/mol, and oxygen (O) has an atomic mass of about 16.00 g/mol. For Li2O, the molar mass is calculated as follows: - There are 2 lithium atoms, so: \( 2 \times 6.94 \, \text{g/mol} = 13.88 \, \text{g/mol} \) - There is 1 oxygen atom, so: \( 1 \times 16.00 \, \text{g/mol} = 16.00 \, \text{g/mol} \) Adding these together gives you the total molar mass of Li2O: \[ 13.88 \, \text{g/mol} + 16.00 \, \text{g/mol} = 29.88 \, \text{g/mol} \] Now, to find the mass of 4.5 moles of Li2O, use the formula:

To determine the mass in grams of 4.5 moles of lithium oxide (Li2O), you first need to calculate the molar mass of Li2O. Lithium (Li) has an atomic mass of approximately 6.94 g/mol, and oxygen (O) has an atomic mass of about 16.00 g/mol.

For Li2O, the molar mass is calculated as follows:

• There are 2 lithium atoms, so:

( 2 \times 6.94 , \text{g/mol} = 13.88 , \text{g/mol} )

• There is 1 oxygen atom, so:

( 1 \times 16.00 , \text{g/mol} = 16.00 , \text{g/mol} )

Adding these together gives you the total molar mass of Li2O:

[ 13.88 , \text{g/mol} + 16.00 , \text{g/mol} = 29.88 , \text{g/mol} ]

Now, to find the mass of 4.5 moles of Li2O, use the formula: