Question

8.
Find the charge of 48 g of Mg2+ ions in coulombs
(1) 2.4 x 1023 (2) 6.82 x 105 c
(3) 3.86 x 105 C (4) 1.93 x 105 c​

Answer 1

No of moles of Mg^+2 ion = given wt/molar wt

here,

given wt = 48 g

molar wt = 24 g/mol

no of moles of Mg^+2 ion = 48/24

= 2 mol

we can see that in one mole of Mg+2 ion , 2 mole electrons occur

so, in two moles of Mg^+2 ions = 2×2 moles of electrons occur .

now, no of electrons = no of mole of electrons× Avogadro's constant

= 4 × 6.023 × 10²³

we also know,

charge of one electron = 1.6× 10^-19 C

so, charge by total electrons = 4 × 6.023 × 10²³ × 1.6 × 10^-19 C

= 38.54 × 10⁴ C

= 3.854 × 10^5 C

Answer 2

Answer:No of moles of Mg^+2 ion = given wt/molar wt

here,

given wt = 48 g

molar wt = 24 g/mol

no of moles of Mg^+2 ion = 48/24

= 2 mol

we can see that in one mole of Mg+2 ion , 2 mole electrons occur

so, in two moles of Mg^+2 ions = 2×2 moles of electrons occur .

now, no of electrons = no of mole of electrons× Avogadro's constant

= 4 × 6.023 × 10²³

we also know,

charge of one electron = 1.6× 10^-19 C

so, charge by total electrons = 4 × 6.023 × 10²³ × 1.6 × 10^-19 C

= 38.54 × 10⁴ C

= 3.854 × 10^5 C

Explanation: