Suppose two elements X and Y combine to form two compounds XY2 and X2Y3 when 0-05 mole of XY2 weights 5 g while 3-011- 1023 molecules of X2Y3 weighs 85 g- The atomic masses of X and Y are respectively-

The correct option is C 40, 30 MassMolar mass = Mole 5gmw = 0.05 ⇒ mw = 100 x+2y = 100 ...(i) No. of molecules6 × 10^23 = massmw eq ...

You visited us 3 times! Enjoying our articles? Unlock Full Access!

Byju's Answer

Standard X

Chemistry

Mole Concept

Suppose two e...

Question

Suppose two elements $X$ and $Y$ combine to form two compounds $X Y_{2}$ and $X_{2} Y_{3}$ when $0.05$ mole of $X Y_{2}$ weights $5$ g while $3.011 \times 10^{23}$ molecules of $X_{2} Y_{3}$ weighs $85$ g. The atomic masses of $X$ and $Y$ are respectively:

20, 30

No worries! We‘ve got your back. Try BYJU‘S free classes today!

30, 40

No worries! We‘ve got your back. Try BYJU‘S free classes today!

40, 30

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

80, 60

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is C $40, 30$
$\frac{M a s s}{M o l a r m a s s} = M o l e$

$\frac{5 g}{m w} = 0.05 \Rightarrow m w = 100$

$x + 2 y = 100 . . . (i)$

$\frac{N o . o f m o l e c u l e s}{6 \times 10^{23}} = \frac{m a s s}{m w}$

eq $(1) \times 2$

$\frac{3.011 \times 10^{23}}{6.023 \times 10^{23}} = \frac{85}{m w} \Rightarrow m w = 170$

$2 x + 3 y = 170 . . . . (i i)$

On solving equation (i) and (ii), we get-
$2 x + 4 y = 200$
$2 x + 3 y = 170$

$y = 30$

$2 \times x + 3 \times 30 = 170$

$2 x = 170 - 90$

$2 x = 80$

$x = 40$

So, the correct option is $C$

Suggest Corrections

Similar questions

Q. Suppose the elements X and Y combine to form two compounds

X Y_{2}

and

X_{3} Y_{2}

. When 0.1 mole of

X Y_{2}

weighs 10 g and 0.05 mole of

X_{3} Y_{2}

weighs 9 g, the atomic weights of X and Y are :

Q. Suppose the elements

X

and

Y

combine to form two compunds

X Y_{2}

and

X_{3} Y_{2}

. when

0.1

mole of

X Y_{2}

weighs

10 g

and

0.05 m o l e

X_{3} Y_{2}

weighs

9 g

, the atomic weights of

X

and

Y

are

Q. Suppose elements

X

and

Y

combine to form two compounds,

X Y_{2}

and

X_{3} Y_{2}

, where

0.1

mol of former weigh

10

g while

0.05

mol of the latter weigh

9

g. What are the atomic weights of

X

and

Y

respectively?

Q. Suppose the elements X and Y combine to form two compounds

X Y_{2}

and

X_{3} Y_{2}

. When 0.1 mole of

X Y_{2}

weighs 10 g and 0.05 mole of

X_{3} Y_{2}

weighs 9 g, the atomic weights of X and Y are

Q. Suppose two elements

X

and

Y

combine to form two compounds

X Y_{2}

and

X_{3} Y_{2}

0.1

mol of former weighs

10

g while

0.05

mol of the latter weighs

9

g. The atomic masses of

X

and

Y

are, respectively:

Join BYJU'S Learning Program

Suppose two elements X and Y combine to form two compounds XY2 and X2Y3 when 0.05 mole of XY2 weights 5 g while 3.011×1023 molecules of X2Y3 weighs 85 g. The atomic masses of X and Y are respectively:

The correct option is C 40,30MassMolarmass=Mole5gmw=0.05⇒mw=100x+2y=100...(i)No.ofmolecules6×1023=massmweq(1)×23.011×10236.023×1023=85mw⇒mw=1702x+3y=170....(ii)On solving equation (i) and (ii), we get- 2x+4y=2002x+3y=170y=302×x+3×30=1702x=170−902x=80x=40So, the correct option is C

Suppose two elements $X$ and $Y$ combine to form two compounds $X Y_{2}$ and $X_{2} Y_{3}$ when $0.05$ mole of $X Y_{2}$ weights $5$ g while $3.011 \times 10^{23}$ molecules of $X_{2} Y_{3}$ weighs $85$ g. The atomic masses of $X$ and $Y$ are respectively: