Question

3. If 2.50 moles of aluminum (Al) are required for a reaction, how many grams of Al are needed? 4. How many grams of lithium (Li) are found in 3.48 x 10 umol of lithium?

Answer 1

3)

Molar mass of Al = 26.98 g/mol

use:

mass of Al,

m = number of mol * molar mass

= 2.5 mol * 26.98 g/mol

= 67.45 g

Answer: 67.4 g

4)

Molar mass of Li = 6.968 g/mol

number of mol = 3.48*10^-2 umol

= 3.48*10^-8 mol

use:

mass of Li,

m = number of mol * molar mass

= 3.48*10^-8 mol * 6.968 g/mol

= 2.425*10^-7 g

Answer: 2.42*10^-7 g