To check the principle of multiple proportions, a series of pure binary compounds ( P m Q n ) were analyzed and their composition is tabulated below. The correct option(s) is(are) Compound Weight % of P Weight % of Q 1 50 50 2 44.4 55.6 3 40 60

Question

To check the principle of multiple proportions, a series of pure binary compounds ( P m Q n ) were analyzed and their composition is tabulated below. The correct option(s) is(are) Compound Weight % of P Weight % of Q 1 50 50 2 44.4 55.6 3 40 60 (A) If empirical formula of compound 3 is P 3 Q 4, then the empirical formula of compound 2 is P 3 Q 5. (B) If empirical formula of compound 3 is P 3 Q 2 and atomic weight of element P is 20 , then the atomic weight of Q is 45 . (C) If empirical formula of compound 2 is PQ, then the empirical formula of the compound 1 is P 5 Q 4 (D) If atomic weight of P and Q are 70 and 35 , respectively, then the empirical formula of compound 1 is P 2 Q.

Tardigrade Admin · Accepted Answer

Compound	Weight % of P	Weight % of Q
1	50	50
2	44.4	55.6
3	40	60

For option (A)
Let atomic mass of

P

be

M_{P}

and atomic mass of

Q

be

M_{Q}

Molar ratio of atoms

P : Q

in compound 3 is

\frac{40}{M _{p}} : \frac{60}{M _{Q}} = 3 : 4

\frac{2 M _{Q}}{3 M _{p}} = \frac{3}{4} \Rightarrow 9 M_{p} = 8 M_{Q}

Molar ratio of atoms

P : Q

in compound 2 is

\frac{44.4}{M _{p}} : \frac{55.6}{M _{Q}}

= 44.4 M_{Q} : 55.6 M_{P}

= 44.4 M_{Q} : 55.6 \times \frac{8 M _{Q}}{9}

= 44.4 : 55.6 \times \frac{8}{9}

= 9 : 10

\Rightarrow

Empirical formula of compound 2 is therefore

P_{9} Q_{10}

Option (A) in incorrect
For option (B)
Molar Ratio of atoms

P : Q

in compound 3 is

\frac{40}{M _{p}} : \frac{60}{M _{Q}} = 3 : 2

\frac{2 M _{Q}}{3 M _{p}} = \frac{3}{2} \Rightarrow 9 M_{p} = 4 M_{Q}

If

M_{P} = 20 \Rightarrow M_{Q} = \frac{9 \times 20}{4} = 45

Option (B) is correct
For option (C)
Molar ratio of atoms

P : Q

in compound 2 is

\frac{44.4}{M _{p}} : \frac{55.6}{M _{Q}} = 44.4 M_{Q} : 55.6 M_{p} = 1 : 1

\Rightarrow \frac{M _{p}}{M _{Q}} = \frac{44.4}{55.6}

Molar ratio of atoms

P

:

Q

in compound 1 is

\frac{50}{M _{p}} : \frac{50}{M _{Q}} = M_{Q} : M_{p}

= 55.6 : 44.4

≃ 5 : 4

Hence, empirical formula of compound 1 is

P_{5} Q_{4}

Hence, option

(C)

is correct
For option (D)
Molar ratio of atoms P : Q in compound 1 is

\frac{50}{M _{p}} : \frac{50}{M _{Q}} = M_{Q} : M_{p}

= 35 : 70 = 1 : 2

Hence, empirical formula of compound 1 is

P Q_{2}

Hence, option (D) is incorrect

Q. To check the principle of multiple proportions, a series of pure binary compounds $(P_{m} Q_{n})$ were analyzed and their composition is tabulated below. The correct option(s) is(are)

Compound Weight % of P Weight % of Q

1 50 50

2 44.4 55.6

3 40 60

If empirical formula of compound 3 is $P_{3} Q_{4}$ , then the empirical formula of compound 2 is $P_{3} Q_{5}$ .

If empirical formula of compound 3 is $P_{3} Q_{2}$ and atomic weight of element $P$ is 20 , then the atomic weight of $Q$ is 45 .

If empirical formula of compound 2 is $PQ$ , then the empirical formula of the compound $1$ is $P_{5} Q_{4}$

If atomic weight of $P$ and $Q$ are 70 and 35 , respectively, then the empirical formula of compound 1 is $P_{2} Q$ .

Q. To check the principle of multiple proportions, a series of pure binary compounds (Pm​Qn​) were analyzed and their composition is tabulated below. The correct option(s) is(are) Compound Weight % of P Weight % of Q 1 50 50 2 44.4 55.6 3 40 60

If empirical formula of compound 3 is P3​Q4​, then the empirical formula of compound 2 is P3​Q5​.

If empirical formula of compound 3 is P3​Q2​ and atomic weight of element P is 20 , then the atomic weight of Q is 45 .

If empirical formula of compound 2 is PQ, then the empirical formula of the compound 1 is P5​Q4​

If atomic weight of P and Q are 70 and 35 , respectively, then the empirical formula of compound 1 is P2​Q.

Q. To check the principle of multiple proportions, a series of pure binary compounds $(P_{m} Q_{n})$ were analyzed and their composition is tabulated below. The correct option(s) is(are)

Compound Weight % of P Weight % of Q

1 50 50

2 44.4 55.6

3 40 60

If empirical formula of compound 3 is $P_{3} Q_{4}$ , then the empirical formula of compound 2 is $P_{3} Q_{5}$ .

If empirical formula of compound 3 is $P_{3} Q_{2}$ and atomic weight of element $P$ is 20 , then the atomic weight of $Q$ is 45 .

If empirical formula of compound 2 is $PQ$ , then the empirical formula of the compound $1$ is $P_{5} Q_{4}$

If atomic weight of $P$ and $Q$ are 70 and 35 , respectively, then the empirical formula of compound 1 is $P_{2} Q$ .