Valency and Oxidation Number

Q.

Calculate the valency of sulphur.

Q.

What is the valency of sulphate ion in $H_{2}S{O}_4$?

1. 6

2. 4

3. 2

4. 1

Q.

State the valency of chloride ion.

Q.

The valency of an ion is equal to its ________.

Q.

Write the valency of Zincate?

Q.

Arrange the following compounds according to the increasing order of oxidation state of chlorine.

$HCl{O}_4,HCl{O}_3,HCl{O}_2,HClO$

1. $HClO<HCl{O}_3<HCl{O}_2<HCl{O}_4$
2. $HClO<HCl{O}_2<HCl{O}_3<HCl{O}_4$
3. $HCl{O}_4<HCl{O}_2<HCl{O}_3<HClO$

4. $HCl{O}_4<HCl{O}_3<HCl{O}_2<HClO$

Q.

How many electrons are present in the kernel of Cl?

1. 7

2. 10

3. 8

4. 12

Q.

Write the formula and valency of ferric.

Q. What is the oxidation state of $Mn$ in $KMn{O}_4$?

1. 7
2. -3
3. -7
4. 3

Q.

Element A and B have 3 and 6 electrons in their outermost shell, respectively.

a) Which element will gain electrons and how many, while forming a chemical compound? What will be the electrical charge on the ion of that element?

b) Which element will lose electrons and how many, while forming a chemical compound? What will be the electrical charge on the ion of that element?

Q.

What is the valency of Chlorine?

1. 10

2. 7

3. 12

4. 8

Q.

Oxidation number is the number indicating the number of oxygen atoms present in the compound.

1. True

2. False

Q. The ratio of the oxidation state of P in $H_{3}P{O}_3$ and $H_{3}P{O}_4$ is

1. 5:3
2. 2:5
3. 5:2
4. 3:5

Q.

What is the oxidation number value of chlorine in $C{l}_2$?

1. +1 for both the chlorine atoms
2. -1 for both the chlorine atoms
3. 0 for both the chlorine atoms
4. +1 for one and -1 for another chlorine atom

Q. The element which has the maximum number of valence electrons is:

1. $Na$
2. $P$
3. $Si$
4. $Al$

Q.

What is the difference between the oxidation number of Mn in $KMn{O}_4$ and $M{n}_2{O}_7$?

1. 2

2. 5

3. 0

4. 3

Q.

Identify the correct statements regarding the following reaction:

$Fe\left(s\right)+O_2\left(g\right)\to F{e}_2{O}_3\left(g\right)$

1. Iron undergoes oxidation

2. Iron undergoes reduction

3. Oxygen undergoes oxidation

4. Oxygen undergoes reduction

Q. How many ammonium ions are present in ammonium sulphate?

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

Q.

What is the oxidation state of Manganese in Manganese (VII) oxide?

1. +7

2. +5

3. +3

4. +1

Q. What is the oxidation state of $Mn$ in $KMn{O}_4$?

1. 7
2. 3
3. -3
4. -7

Q.

Which of the given chemical formula is not possible for the elements given below along with their valency.

Element P - 1

Element Q - 2

Element R - 1

Element S - 4

1. $P_{2}Q$

2. $Q{R}_2$

3. $S{R}_4$

4. $S_2{Q}_4$

Q. is the actual charge of an atom if it exists as a monoatomic ion.

1. Atomic number
2. Mass number
3. Oxidation number

Q.

What is the chemical formula for aluminium oxide?

1. ${Al}_2{O}_3$

2. ${Al}_3{O}_2$

3. $Al{O}_2$

4. ${Al}_{2}O$

Q. Question 1 (iii)
Write down the formulae of:
(iii) Sodium sulphide

Q.

What is the combining capacity of an element called?

1. Oxidation state

2. Oxidation number

3. Polarity

4. Valency

Q.

What is the valency of a carbon atom?

1. 1

2. 2

3. 4

4. 3

Q. Question 1 (i)
Write down the formulae of:
(i) Sodium oxide

Q. Element Y accepts 3 electrons from element X to form a molecule. Guess the element Y and X from the options given below.

1. Y = Oxygen and X = Magnesium
2. Y = Nitrogen and X = Aluminium
3. Y = Oxygen and X = Sodium
4. Y = Carbon and X = Magnesium