Question 130.2 g atom of silicon combine with 21.3 g of chlorine. Find the empirical formula of the compound formed.

Question

Accepted Answer

Gram atom = Mass of elementAtomic mass\dfrac{	ext{Mass of element}}{	ext{Atomic mass}}Atomic massMass of element​g atom of silicon = 0.2 = Mass of silicon28\dfrac{	ext{Mass of silicon}}{28}28Mass of silicon​∴ Mass of silicon = 5.6 g andMass of chlorine = 21.3 gElementMassAt. wt.gram atomsSimplest ratioSilicon5.6285.628\dfrac{5.6 }{28}285.6​ = 0.20.20.2\dfrac{0.2 }{0.2}0.20.2​ = 1Chlorine21.335.521.335.5\dfrac{ 21.3}{35.5}35.521.3​ = 0.60.60.2\dfrac{ 0.6 }{0.2}0.20.6​ = 3Simplest ratio of whole numbers = Si : Cl = 1 : 3Hence, empirical formula is SiCl3

Element	Mass	At. wt.	gram atoms	Simplest ratio
Silicon	5.6	28	$\dfrac{5.6 }{28}$ = 0.2	$\dfrac{0.2 }{0.2}$ = 1
Chlorine	21.3	35.5	$\dfrac{ 21.3}{35.5}$ = 0.6	$\dfrac{ 0.6 }{0.2}$ = 3

Mole Concept and Stoichiometry — Question 13

Question 13