Molecular Weight

Q.

What is the mass ratio of hydrogen to oxygen in a water molecule?

1. 2:3

2. 1:8

3. 1:4

4. 1:16

Q.

Percentage of calcium in calcium carbonate is ________.

Q.

The number of molecules present in 16 g of SO₂ is 3×10²³.

1. True
2. False

Q.

What is the molecular mass of Ethanoic acid?

Q.

What is the molecular mass of a substance, each molecule of which contains 9 carbon atoms, 13 hydrogen atoms and $2.33\times {10}^{-23}$ g of another component?

1. 135.04
2. 100
3. 28
4. 111

Q.

One mole of $H_{2}O$ corresponds to

1. 6.022 *10²³ atoms of hydrogen and oxygen.

2. 22.4 L at 1 atm

3. 1 g

4. 18 g

Q.

The Atomic mass of Lead is $207$. How many times the atoms of Lead are Heavier than Carbon atom?

Q.

Calculate the formula mass of Potassium nitrate $\left({\mathrm{KNO}}_3\right)$.

Given: Atomic masses of K = 39u, N = 14u, 0 = 16u

Q.

How many moles of ${\mathrm{SO}}_2$ have same mass as $3$ moles of Oxygen ?(Atomic mass : $\mathrm{S}$ = $32$, $\mathrm{O}$ = $16$)

Q.

(i) Calculate the mass of 3.011 x 1023 nitrogen molecules.
(ii) How many moles are 12.044 x 1023 atoms of He?

Q.

Calculate the molar mass of Sulphuric acid ${\mathrm{H}}_2{\mathrm{SO}}_4$.

Q.

What is the Weight of a molecule of the compound C₆₀H_122?

Q.

The number of atoms present in $4.25grams$ of $N{H}_3$ is approximately

1. 1 X 10²³

2. 1.5 X 10²³

3. 2 X 10²³ NH3

4. 6.02 X 10²³

Q.

The molecular mass of Na₂CO₃ is ___.

Q.

Ratio of number of atoms in one mole of oxygen to ozone is _____

1. 

2. 

3. 

4. 

Q.

According to the law of conservation of mass, 3 g of carbon burnt in 8 g of oxygen forms 11 g of carbon dioxide. Now, what will be the mass of carbon dioxide produced when 3 g of carbon is burnt in 50 g of oxgyen?

1. 45 g

2. 47 g

3. 53 g

4. 50 g

Q.

According to the law of conservation of mass, 3 g of carbon burnt in 8 g of oxygen forms 11 g of carbon dioxide. Now, what will be the mass of carbon dioxide produced when 3 g of carbon is burnt in 50 g of oxgyen?

1. 45 g

2. 47 g

3. 53 g

4. 50 g

Q. Question 30
A sample of vitamin C is known to contain $2.58\times {10}^{24}$ oxygen atoms. How many moles of oxygen atoms are present in the sample?

Q. __________________ is the number of times one molecule of the substance is havier than 1/12 the mass of an atom of carbon \[(C^{12}\)].

1. Relative atomic mass
2. Gram atomic mass
3. Gram molecular mass
4. Relative molecular mass

Q.

Question 11
Calculate the number of aluminium ions present in 0.051 g of aluminium oxide.

Q.

The molecular formula of a compound is $C_2$$X_6$. X is unknown . If the mass ratio of C to X is 4:1. Find X.

1. Helium

2. Sodium

3. Calcium

4. Hydrogen

Q. In a chemical reaction, reactant A gets completely converted to B and C as shown below.
A $\to$ B + C

If the masses of A and C are 40 g and 10 g respectively, the mass of B will be ______.

1. 20.5 g
2. 28 g
3. 30 g
4. 18 g

Q.

Mass of $6.022$ atoms of an element is called Atomic mass

1. True
2. False

Q.

Calculate the molecular mass of $\left({\mathrm{CH}}_3\mathrm{OH}\right)$

Given Atomic masses: C = 12u, H = 1u, O = 16u

Q.

How many moles in 9.033× ${10}^{23}$atoms of hydrogen.

1. 1

2. 2

3. 1.5

4. 3

Q.

The molecular formula of a compound is $C_2{X}_6$ . X is unknown.If the mass ratio of C to X is 4:1. Find X

1. Helium

2. Sodium

3. Hydrogen

4. Calcium

Q.

What is the mass of 10 moles of $H_{2}O$?

1. 180 g

2. 18 g

3. 1.8 g

4. 1800 g

Q. How many molecules are present in one gram of hydrogen ($H_2$)?

1. $6.023\times {10}^{22}$
2. $3.01\times {10}^{23}$
3. $3.0125\times {10}^{-12}$
4. $6.023\times {10}^{23}$

Q. The number of moles in $2\times {10}^{24}$ atoms of iron are

1. 3.3
2. 5.2
3. 2.1
4. 4.5

Q. In a chemical reaction, the total mass of the reactants is 50 g. What will be the total mass of the products formed?

1. 40 g
2. 100 g
3. 50 g
4. 25 g