Law of Conservation of Mass

Q.

How many grams of dibasic acid (molar mass $200$) should be present in $100\mathrm{ml}$ of aqueous solution to give $0.1\mathrm{N}$.

Q.

what is law of conservation of mass??

Q.

In a chemical reaction, the total mass of the reactants is equal to the total mass of ___

Q.

What is incorrect about the Law of conservation of mass?

A. It was given by Antoine Lavoisier

B. Given compound always contains exactly the same proportion of elements by weight

C Mass of reactants is equal to the mass of products

D Matter can neither be created nor destroyed

Q.

(a) State the law of conservation of mass.

(b) What do you observe when barium chloride solution is mixed with sodium sulphate solution ?

Q.

Assertion: In a chemical reaction, the total mass of the products remains same as the total mass of the reactants.

Reason: A chemical reaction involves simply the exchange of atoms and no new species are formed.

1. If both assertion and reason are correct and the reason is the correct explanation for assertion.

2. If both assertion and reason are correct but the reason is not the correct explanation for assertion.

3. If the assertion is correct but the reason is incorrect.

4. If the assertion is incorrect but the reason is correct.

Q. In a chemical reaction, 300 grams of reactant A combines with 100 grams of reactant B to give a product C. Both A and B react completely. How much will product C weigh?​

Q.

What is the mass (in grams) of 2.5 moles of slaked lime, $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$?

Q.

If 10 gms of $Mg$ react with 20 gms of $O_2$, then how many grams of $MgO$ is formed?

1. 20

2. 25

3. 30

4. 15

Q.

$6.022\times {10}^{20}$ atoms of silver (at. mass 108 u) weigh

1. $108\times {10}^3\mathrm{g}$

2. $108\mathrm{g}$

3. $0.108\mathrm{g}$

4. $10.8\mathrm{g}$

Q.

What does the following statement mean? In a chemical reaction, the total mass of the reactants is equal to the total mass of the products.

1. Chemical energy nullifies the mass

2. Those reactions are reversible

3. There is no change in the mass during a chemical reaction

4. Catalysts used will make up for the lost mass

Q. How much mass of silver nitrate will react with 5.85 g of sodium chloride to produce 14.35 g of silver chloride and 8.5 g of sodium nitrate if the law of conservation of mass is followed?

1. 22.85 g
2. 108 g
3. 17.0 g
4. 28.70 g

Q.

What is the mass of carbon dioxide if carbon is 12 and oxygen is 16.

1. 42

2. 44

3. 46

4. 48

Q.

Who proposed the law of conservation of mass?

1. Dalton

2. Maharshi Kannad

3. Democritus

4. Lavoisier

Q.

State law of conservation of mass.

Q.

The ratio by mass of C and O in ${\mathrm{CO}}_2$ is-

1. 1:2

2. 3:14

3. 3:8

4. 3:11

Q.

Ram was carrying out a chemical reaction in a test tube, but accidentally he forgot to put the cork on the test tube.
In this situation, the law of conservation of mass is followed.

1. True

2. False

Q. State the law of conservation of mass

Q.

In a experiment 5.0 g of CaCO₃ on heating gave 2.8 g of CaO and 2.2 g of CO₂. The results are in accordance to the

(A)law of conservation of mass
(B)law of constant proportion
(C)law of multiple proportion
(D)law of reciprocal proportion

Q.

What is the mass of sulphur in combination with 5 g of iron in ferrous sulphide $\left(FeS\right)$.

1. 2.3 gm

2. 2.9 gm

3. 1.9 gm

4. 3.2 gm

Q.

Cinnabar ($\mathrm{HgS}$) is a prominent ore of mercury. How many grams of mercury are present in 225 g of pure$\mathrm{HgS}$?

Molar mass of $\mathrm{Hg}$ and $\mathrm{S}$are 200.6 g ${\mathrm{mol}}^{-1}$ and 32 g ${\mathrm{mol}}^{-1}$respectively.

Q. Calculate the mass of calcium carbonate which decomposes to produce :
(1)50 g of calcium oxide and
(2)5 g of carbon dioxide.
(Atomic mass of Ca = 40, C = 12 and O = 16)

Q. In the chemical reaction shown below, the mass of water formed is _______.

Acid + Base $\to$ Salt + Water
35 g 40 g 57 g ?

1. 16.25
2. 18
3. 20
4. 24.5