Question 4(ii)If 6.21 g of lead is combined with 4.26 g of chlorine, what is the empirical formula of the compound formed?(At. wt. Lead = 207, Chlorine = 35.5).

Question

Accepted Answer

ElementMass (g)Atomic massMolesSimplest ratioPb6.212076.21207\dfrac{6.21}{207}2076.21​ = 0.030.030.03\dfrac{0.03}{0.03}0.030.03​ = 1Cl4.2635.54.2635.5\dfrac{4.26}{35.5 }35.54.26​ = 0.120.120.03\dfrac{0.12}{0.03}0.030.12​ = 4Simplest ratio of whole numbers Pb : Cl = 1 : 4Hence, empirical formula is PbCl4

Element	Mass (g)	Atomic mass	Moles	Simplest ratio
Pb	6.21	207	$\dfrac{6.21}{207}$ = 0.03	$\dfrac{0.03}{0.03}$ = 1
Cl	4.26	35.5	$\dfrac{4.26}{35.5 }$ = 0.12	$\dfrac{0.12}{0.03}$ = 4

Model Paper 3 — Question 6

Question 4(ii)