Atoms and Molecules

Q.

Which one of the following properties of an element can never be variable?

1. Valency

2. Atomic weight

3. Equivalent Mass

4. All the above

Q.

Mass of 1 atom of Hydrogen is _____

1. 1.66 g

2. 6.022 g

3. 6.022 g

4. 1.67 g

Q.

1 mole of He gas has 6.022$\times$10x atoms. x is _____

1. 20

2. 23

3. 25

4. 30

Q.

Number of gram atoms of oxygen present in $0.3mole$ of $(COOH{)}_2.2H_{2}O$ is

1. 0.9

2. 18

3. 1.8

4. 9

Q. If we consider that $\frac{1}{6}$, in place of $\frac{1}{12}$, mass of carbon atom is taken to be the relative atomic mass unit, the mass of one mole of a substance will

1. Decrease twice
2. Increase two fold
3. Remain unchanged

4. Be a function of the molecular mass of the substance

Q.

How many oxygen atoms are present in 50g of $CaC{o}_3$ ?

1. 12.044

2. 6.022

3. 3.011

4. 9.033

Q.

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

1. 

2. 

3. 

4. 

Q.

1 mole of $N_2$ has _____ number of atoms

1. 6.022 $\times$ ${10}^{23}$
2. 3.011 $\times$ ${10}^{23}$
3. 12.044 $\times$ ${10}^{23}$
4. 6.022 $\times$ ${10}^{22}$

Q. How many molecules are present in 9g of water?

1. 6.022$\times$ ${10}^{23}$
2. 3.011$\times$ ${10}^{23}$
3. 6.022$\times$ ${10}^{25}$
4. 3.011$\times$ ${10}^{20}$

Q.

The specific heat of a metal is 0.16 its approximate atomic weight would be

1. 32

2. 16

3. 40

4. 64