Law of Constant Proportion

Q. The mass ratio of copper and oxygen in samples of CuO obtained by different methods were found to be same. This illustrates the:

1. law of conservation of mass
2. law of constant proportion
3. Avogadro's law
4. law of multiple proportion

Q. The relative molecular mass of a substance expressed in grams is known as _____________.

1. gram molecular mass
2. gram atomic mass
3. average atomic mass
4. average molecular mass

Q.

In Ammonia ${\mathrm{NH}}_3$ there are three hydrogen atoms and one nitrogen atom but still the percentage composition of nitrogen is higher. Discuss.

Q. Hydrogen combines with oxygen in1:8 in water if 9g of water is decomposed 1g of hydrogen and 8g of hydrogen is always formed what if 10 g of water. what amount of hydrogen and oxygen we will get.how?

Q. stated that matter is neither created nor destroyed.

1. Antoine Lavoisier
2. Ernest Rutherford
3. Henry Cavendish

Q. grams of hydrogen are required to react with 36 grams of carbon to form methane (${\text{CH}}_4$).

1. 12
2. 24
3. 72
4. 108

Q. Three oxides of lead contain 92.83% , 90.65% and 86.10% lead. Prove that the law of multiple proportions is verified from these data.

Q.

Calculate the relative molecular mass of carbon dioxide (CO₂) .

1. 38

2. 44

3. 46

4. 42

Q. The mass ratio of elements in a molecule are given below. Which among the following is incorrect with respect to law of constant proportion?

1. $N{H}_3$, H:N mass ratio = 3:14
2. $H_{2}O$, O:H mass ratio = 8:1
3. ${\mathrm{CO}}_2$, O:C mass ratio = 8:3
4. CO, O:C mass ratio = 5:3

Q. Rohan found out that the ratio of nitrogen to hydrogen particles in a sample of ammonia from his lab was 1:3, by mass. Next day he collected an ammonia sample from a different lab. Which of the following will be the ratio of nitrogen to hydrogen particles in this sample?

1. 1:2
2. 1:3
3. 1:1
4. 1:4

Q. A sample of Ethane gas has the same mass as 1.5*10^20 molecules of Methane. How many ethane sample of gas contain?

Q. State law of constant proportions.

Q. Question 4
Dalton's atomic theory successfully explained.

(i) law of conservation of mass
(ii) law of constant composition
(iii) law of radioactivity
(iv) law of multiple proportions

(a) (i), (ii) and (iii)
(b) (i), (iii) and (iv)
(c) (ii), (iii) and (iv)
(d) (i), (ii) and (iv)

Q. The relative molecular mass of a substance expressed in grams is known as _____________.

1. gram molecular mass
2. gram atomic mass
3. average atomic mass
4. average molecular mass

Q. Rohan found out that the ratio of nitrogen to hydrogen particles in a sample of ammonia from his lab was 14:3 by mass. Next day he collected an ammonia sample from a different lab. Which of the following will be the mass ratio of nitrogen to hydrogen in this sample?

1. 3:14
2. 3:1
3. 1:3
4. 14:3

Q. How much amount of $N{H}_3$ is produced when 28 g of nitrogen react with 6 g of hydrogen?

1. 28 g
2. 6 g
3. 34 g
4. 32.5 g

Q. <!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> What are the key postulates of Dalton atomic theory?

Q. The number of hydrogen atoms that are present in the molecular formula of methane is ______.

1. one
2. two
3. three
4. four

Q.

In water, the mass ratio of hydrogen to oxygen is always 1:8.

1. True

2. False

Q.

A sample containing 85 gm of NH₃ is decomposed into nitrogen and hydrogen. The total amount of nitrogen and hydrogen present in 85 gm of the sample respectively are:

1. 70, 15

2. 15, 70

3. 56, 20

4. 71, 14

Q.

X and Y chemically react to form a new product Z.

X+Y→ Z

The masses of X and Y are 5 g and 6 g respectively. The mass of Z is _______ g.

1. 6
2. 10
3. 11
4. 5

Q.

Question 4
Which postulate of Dalton’s atomic theory can explain the law of definite proportions?

Q.

Daltons atomic theory successfully explained

(i) Law of conservation of mass

(ii) Law of constant composition

(iii) Law of radioactivity

(iv) Law of multiple proportion

1. (i), (ii), and (iii)

2. (i), (iii), and (iv)

3. (ii), (iii), and (iv)

4. (i), (ii), and (iv)

Q. Law of constant proportion states that a chemical compound always contains the same elements combined in a fixed proportion by mass.

1. False
2. True

Q. The mass ratio of copper and oxygen in samples of CuO obtained by different methods were found to be same. This illustrates the:

1. law of conservation of mass
2. Avogadro's law
3. law of constant proportion
4. law of multiple proportion

Q. The mass ratio of elements in a molecule are given below. Which among the following is incorrect with respect to law of constant proportion?

1. $N{H}_3$, H:N mass ratio = 3:14
2. $H_{2}O$, O:H mass ratio = 8:1
3. ${\mathrm{CO}}_2$, O:C mass ratio = 8:3
4. CO, O:C mass ratio = 5:3

Q. The total amount of matter before and after a chemical reaction remains the same.

1. False
2. True

Q. Who proposed the law of constant proportions?

1. John Dalton
2. Joseph Proust
3. Antoine Lavoisier
4. Ernest Rutherford