Variable Valency

Q.

What is/are valencies of Mercury?

1. 1

2. 2

3. 3

4. 4

Q.

Cupric is the name of copper having it's valency 1.

1. True

2. False

Q.

Valency of iron for Ferric compounds is 3.

1. True

2. False

Q.

4. Derive the molecular formulae of the following compounds stepwise and give their atomicity.

i. ammonium sulphate

Q.

Write the formula and names of the compounds formed between :
Sodium and sulphide ions

Q.

Based on what is the chemical formula of an ionic compound determined?

1. mass

2. valency

3. atomic number

4. charge

Q.

THIS IS THE QUESTION TAKEN FROM 1985 BOARD ICSE PAPER OF 10TH XCL2 is the chloride of a metal X.state the formula of the sulphate and hydroxide of the metal X

Q. X is an ionic compound containing only magnesium aluminium and oxygen. What is the formula of the compound?

Q.

If the aluminium salt of an anion X is $A{l}_2{X}_3$, What is the valency of X ? What will be the formula of the magnesium salt of X?

Q.

The valencies of magnesium and oxygen respectively are:

1. +2, -2

2. 2, 2

3. -2, -2

4. -2, +2

Q. An element E forms an oxide EO².write the valency of E and chemical formula of its chloride.

Q.

Write the chemical formula for sodium sulphite?

Q.

In a chemical formula of a diatomic ionic compound, the valency of the anion is 3.Find out the valency of the cation.

1. Cannot be determined

2. Less than 4

3. More than 4

4. Equal to 4

Q.

Which of the following polyatomic ions does not have a valency of −1?

1. OH
2. NH₄
3. SO₄
4. NO₃

Q.

Derive the molecular formulae of the following compounds stepwise and give their atomicity.

Hydrogen chloride

Q.

If the aluminium salt of an anion X is $A{l}_2{X}_3$, What is the valency of X ? What will be the formula of the magnesium salt of X?

Q. What are the variable valencies exhibited by iron?

1. 2, 3
2. 1, 2

Q. Why iron sometimes has 2 as valency and sometimes three as valency?

Q.

When chlorine reacts with metals having variable valencies, the
chloride of the metal with higher valency is formed. Why?

Q. What does the following statement mean?
Primary valencies are non directional whereas secondary valencies are directional.

Q.

Which of the following cations has valency of 2?

1. Aluminium

2. Potassium

3. Sodium

4. Zinc

Q. The chemical formula of the ionic compound containing ${Fe}^{3+}$ and $(S{O}_4{)}^{2-}$is____.

1. ${Fe}_{2}S{O}_4$
2. ${Fe}_3(S{O}_4{)}_2$
3. ${Fe}_2(S{O}_4{)}_3$
4. ${Fe}_{3}S{O}_4$

Q.

Write the name of the Compound $\mathrm{Mg}{\left({\mathrm{NO}}_3\right)}_2$

Q.

Elements with valency $1$ are:

1. Always metals

2. Always metalloids

3. Either metals or non-metals

4. Always non-metals

Q. The chemical formula of the ionic compound containing ${Fe}^{3+}$ and $(S{O}_4{)}^{2-}$is____.

1. ${Fe}_{2}S{O}_4$
2. ${Fe}_3(S{O}_4{)}_2$
3. ${Fe}_2(S{O}_4{)}_3$
4. ${Fe}_{3}S{O}_4$

Q.

Why does iron have two valencies?

Q. Which of the following ions form most stable complex compound?

1. $N{i}^{++}$
2. $F{e}^{++}$
3. $C{u}^{++}$
4. $M{n}^{++}$

Q.

Arrange the following elements in increasing order of their valency.

Boron, Beryllium, Lithium

Q. An element X has a Valency 2:
(a)Write the chemical formula of its oxide
(b)Write the chemical formula of its carbonate
(c)Is element X a metal or non- metal?

Q.

2. What is the formula of the compound formed by the element in group 1A and period 3 and the element in group VIA and period 2 of the periodic table?