if the oxides of a metal contain 78.7% and 64.5% of oxygen and if the formula of the first oxide is MO, find the formula of other oxide, the ration of oxygen in two oxide is 1:3
Answers
Given info : if the oxides of a metal contain 78.7% and 64.5% of oxygen and if the formula of the first oxide is MO.
To find : the formula of the other oxide. The ratio of oxygen in two oxides is 1 : 3.
Case 1 : oxygen = 78.7 % so metal = 100 - 78.7 = 21.3 %
Let atomic mass of metal is M
Percentage mass of metal = M/(M + 16) × 100
⇒21.3 = 100M/(M + 16)
⇒21.3M + 21.3 × 16 = 100M
⇒21.3 × 16 = 78.7 M
⇒M = 4.33
Now, let formula of the other oxide is MxOy then,
Percentage of metal = xM/(xM + yO) × 100
⇒100 - 64.5 = x4.33/(x4.33 + y16) × 100
⇒35.5 = 433x/(4.33x + 16y)
⇒4.33x × 35.5 + 16y × 35.5 = 433x
⇒153.7x + 568y = 433x
⇒568y = 279.3x
⇒y/x = 279.3/568 ≈ 0.5 = 1/2
Therefore the formula of the other is M₂O
Answer :-
Given info : if the oxides of a metal contain 78.7% and 64.5% of oxygen and if the formula of the first oxide is MO.
To find : the formula of the other oxide. The ratio of oxygen in two oxides is 1 : 3.
Case 1 : oxygen = 78.7 % so metal = 100 - 78.7 = 21.3 %
Let atomic mass of metal is M
Percentage mass of metal = M/(M + 16) × 100
⇒21.3 = 100M/(M + 16)
⇒21.3M + 21.3 × 16 = 100M
⇒21.3 × 16 = 78.7 M
⇒M = 4.33
Now, let formula of the other oxide is MxOy then,
Percentage of metal = xM/(xM + yO) × 100
⇒100 - 64.5 = x4.33/(x4.33 + y16) × 100
⇒35.5 = 433x/(4.33x + 16y)
⇒4.33x × 35.5 + 16y × 35.5 = 433x
⇒153.7x + 568y = 433x
⇒568y = 279.3x
⇒y/x = 279.3/568 ≈ 0.5 = 1/2
Therefore the formula of the other is M₂O