Answer:
Mass of Mg = 120 g
1.23 moles of Cu
Explanation:
A)
Given data:
Number of moles of Mg = 5 mol
Mass of Mg = ?
Solution:
Number of moles = mass/molar mass
Molar mass of magnesium is 24 g/mol.
5 mol = mass/ 24 g/mol
Mass = 5 mol × 24 g/mol
Mass = 120 g
B) Given data:
Number of atoms of Cu = 7.4 ×10²³ atom
Number of moles of Cu = ?
Solution:
Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
7.4 ×10²³ atom × 1 mol / 6.022 × 10²³ atom
1.23 moles of Cu
