Question

Plz tell me the answer of these question's of chapter-3 atoms & molecules!
Q1. Copper oxide was prepared by 2 different methods in one case 1.75g of the metal gave 2.19g of the oxide in the second case 1.14g o the metal gave 1.43g of the oxide. Show that the given data proves law of constant proportion.
Q2. Calculate the mass of carbon present in 2g of CO2.

Law of constant helps us to calculate the percentage of any element by the following formula:-

% of an element in the compound
=mass of the element
Upon ×100
Mass of compound

Plz tell me the answer its urgent

Answer 1

2.CO2 has the ratio :- 12:32 or 3:8 as it is 2 g it is *2

Answer 2

Answer:

2) $\dfrac{6}{11}$

Explanation:

QUESTION 1:

Experiment 1:

Mass of Copper = 1.75 g

Mass of Copper Oxide = 2.19 g

Mass of Oxygen = 2.19 - 1.75 = 0.44

Experiment 2:

Mass of Copper = 1.14 g

Mass of Copper Oxide = 1.43

Mass of Oxygen = 0.29

Ratio of Copper to Oxygen in:

Experiment 1 = $\dfrac{175}{44}$ = 3.9

Experiment 2 = $\dfrac{114}{29}$ = 3.9

We can clearly see that , in both the experiments the ratio of Copper to Oxygen is fixed.

Therefore, Law of Constant Proportion is followed.

QUESTION 2:

Mass of $\sf{{CO}_{2}}$ = 12 + 16*2 = 12+32 = 44g

44g $\sf{{CO}_{2}}$ has 12 g Carbon

1g $\sf{{CO}_{2}}$ will have $\dfrac{12}{44}$

12g $\sf{{CO}_{2}}$ will have $\dfrac{12}{44} \times 2$

Therefore , 12g $\sf{{CO}_{2}}$ will have $\dfrac{6}{11}$