Atoms and Molecules

Q. The total no of ions present in 111 g of $CaC{l}_2$ is

1. Two mole
2. One mole
3. Three mole
4. Four mole

Q. The ratio of hydrogen to oxygen atoms, in a water molecule is:

1. 1 : 2
2. 2 : 4
3. 1 : 3
4. 2 : 1

Q.

What is the difference between homoatomic and heteroatomic molecules?

Q. A molecule which is made up of atoms of the same element is called molecule.

1. heteroatomic
2. monoatomic
3. homoatomic

Q.

Which kind of molecules is made up of atoms of the same element?

1. Heteroatomic molecules

2. Homoatomic molecules

3. Atomic molecules

4. Atoms

Q.

Largest number of ions is present in the electrolyte

1. 50 g K₂SO₄(mol. wt. 174)

2. 50 gNH₄CL (mol. wt. 53.5)

3. 50 gCaCL₂ (mol. wt. 111)

4. 50 g NaCl (mol. wt. 58.5)

Q. How many molecules of ${\text{H}}_2$ gas are present in a container of dimensions 2 m $\times$ 2 m $\times$ 3 m at STP?

1. $32.22\times {10}^{25}$

2. $32.22\times {10}^{23}$

3. $32.22\times {10}^{22}$

4. $32.22\times {10}^{27}$

Q. In the ions $P^{3-},S^{2-}$ and $C{l}^{-}$ the increasing order of size is:

1. $C{l}^{-}<S^{2-}<P^{3-}$
2. $P^{3-}<S^{2-}<C{l}^{-}$
3. $S^{2-}<C{l}^{-}<P^{3-}$
4. $S^{2-}<P^{3-}<C{l}^{-}$

Q. Consider the isoelectronic ions:
$K^{+},S^{2-},C{l}^{-}$ and $C{a}^{2+}$
The radii of these ionic species follow the order:

1. $C{a}^{2+}>K^{+}>C{l}^{-}>S^{2-}$
2. $C{l}^{-}>S^{2-}>K^{+}>C{a}^{2+}$
3. $S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$
4. $K^{+}>C{a}^{2+}>S^{2-}>C{l}^{-}$

Q. What is the molar mass of ${\text{NH}}_3$?

1. 17

Q.

The total no of ions present in 111 g of $CaC{l}_2$ is

1. One mole

2. Three moles

3. Two moles

4. Four moles

Q.

The total no of ions present in 111 g of $CaC{l}_2$ is

1. Three moles
2. One mole
   
3. Two moles
   
4. Four moles

Q. Arrange the following ions in order of their increasing radii.
$L{i}^{+},M{g}^{2+},K^{+},A{l}^{3+}$:

1. $A{l}^{3+}<M{g}^{2+}<L{i}^{+}<K^{+}$
2. $A{l}^{3+}<M{g}^{2+}<K^{+}<L{i}^{+}$
3. $M{g}^{2+}<A{l}^{3+}<L{i}^{+}<K^{+}$
4. None of these

Q. The mass of 2 grams of atoms of calcium is :

1. 2 g
2. 0.05 g
3. 0.5 g
4. 80 g

Q. $K^{+},C{l}^{-},C{a}^{2+},S^{2-}$ ions are isoelectronic. The decreasing order of their size is :

1. $S^{2-}>C{l}^{-}>K^{+}>C{a}^{2+}$
2. $C{a}^{2+}>K^{+}>C{l}^{-}>S^{2-}$
3. $K^{+}>C{l}^{-}>C{a}^{2+}>S^{2-}$
4. $Cr>S^{2-}>C{a}^{2+}>K^{+}$

Q.

The symbol of Phosphorous is

1. P

2. Pd

3. Pb

4. Pt

Q.

The degree of hotness and coldness of an body.

Q. How many moles of atoms are present in 7.36 × 10²⁴ free oxygen atoms?

1. 11.4 moles
2. 10.2 moles
3. 13.4 moles
4. 12.2 moles

Q. The number of chloride ions present in $0.5$ mole of $MgC{l}_2$ is:

1. $2N_A$
2. $N_A/4$
3. $N_A/2$
4. $N_A$

Q. When the $s$ block elements react, do they donate or accept electrons?

Q. The mass of one steel screw is 4.11 g. Find the mass of one mole of these steel screws.

Q.

Name a device used for measurement of temperature.

Q.

If one mole of carbon atoms weighs 12 grams, what is the mass (in gram) of 1 atom of carbon? [3 MARKS]