Question

Use dimensional analysis to solve the following problems. Pay attention to correct use of units and correct use of significant figures in calculations.

1) Convert 8.00 moles of aluminum to grams.

2) Convert 10.5 moles of aluminum chloride to grams.

Answer 1

#1

• Molar mass of Al=27g/mol

1mol.of Al=27g

8mol of Al=27(8)=216g

#2

Molar mass of AlCl3=133.5g/mol

1 mol of AlCl3=133.5g

10.5mol.of AlCl3=10.5(133.5)=1401.75g

Answer 2

Solution given:

1:

1 mole of aluminum =26.98 gram

8 mole =26.98*8=215.84 gram

8.00 moles of aluminum =215.84grams.

2:

1 mole of aluminum chloride =133.34 grams

10.5 moles of aluminum chloride =133.34*10.5=1400.07 grams

10.5 moles of aluminum chloride =1400 grams.