Question

IDENTIFY THE CORRECT STATEMENTS.

1. IN A COMPOUND SUCH AS WATER, THE RATIO OF THE MASS OF HYDROGEN TO THE MASS OF OXYGEN IS ALWAYS 8: 1.

2. IF 9G OF WATER IS DECOMPOSED, 1 G OF HYDROGEN AND & G OF OXYGEN ARE ALWAYS OBTAINED.

3. WATER TAKEN FROM LAKE AND SEA WILL HAVE DIFFERENT PROPORTION OF THE ELEMENTS PRESENT.

4. MANY COMPOUNDS ARE COMPOSED OF TWO OR MORE ELEMENTS AND EACH SUCH COMPOUND HAS THE SAME ELEMENTS IN THE SAME PROPORTIONS.

(A) I AND 3
(B) 1,2 AND 3
(C) 2 AND 4
(D) ALL OF THESE

no copied answer otherwise u'll be reported (class 9)​

Answer 1

★$\textbf{Question:-}$

»Identify the correct statements

★$\textbf{To do:-}$

»Analyze the statements one by one

★$\textbf{Analyzing the statements:-}$

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

Ans-Incorrect Statement

The ratio of the mass of hydrogen to the mass of oxygen is always 1:8,no matter from what source water is obtained.

2.If 9 g of water is decomposed, 1 g of hydrogen and 8 g of oxygen are always obtained.

Ans-Correct Statement

If 9 g of water is decomposed, 1 g of hydrogen and 8 g of oxygen are always obtained since hydrogen and oxygen are present in the ratio 1:8 in water.

3.Water taken from lake and sea will have different proportion of the elements present.

Ans-Incorrect Statement

Water taken from lake and sea will have same proportion of the elements present which is in the ratio of 1:8 by the law of definite proportion i.e, in a chemical compound the elements are always present in a definite ratio by mass from whatever source it is obtained.

4.Many compounds are composed of two or more elements and each such compound has the same elements in the same proportions.

Ans-Correct Statement

Lavoisier and some other scientists discovered that many compounds were composed of two or more elements and each such compound had the same elements in the same proportions.This comes under the law of constant proportions.

★$\textbf{Answer:-}$

Since,the correct statements are 2 and 4 respectively.

Therefore, option (C) 2 and 4 is the correct answer.