Question

Write the formula of the following salts by criss-cross 1 Mercury(II) bromide​

Answer 1

1. Valency of sodium- 1+

valency of HCO3- 1-

formula- NaHCO3

2. Valency of Fe- 2+

valency of SO4- 2-

formula- FeSO4

3. valency of Al- 3+

valency of N- 3-

formula- AlN

4. valency of K- 1+

valency of SO4- 2-

formula- K2SO4

5. valency of NH4- 1+

valency of CI- 1-

formula- NH4Cl

6. valency of Pb- 2+

valency of NO3- 1-

formula-Pb(NO3)2

7. valency of NH4- 1+

valency of PO4- 3-

formula- (NH4)3PO4

8. valency of Cu- 2+

valency of O- 2-

formula- CuO

9. valency of Ca- 2+

valency of OH- 1-

formula-Ca(OH)2

10. valency of Zn- 2+

valency of OH- 1-

formula- Zn(OH)2

Note: crossing method cannot be shown here.

Answer 2

Answer:

The formula of Mercury(II) bromide​ is HgBr₂

Explanation:

Crisscross Method for formula writing:

1. Write the symbol and charge of the metal ( cation) first and then non-metal(anion).
2. Cross over the numerical value of ion charges and write as a subscript of the other ion
3. Reduce it to the lowest whole-number ratio.

Here, Hg has a valency of 2 while bromide has a valency of 1. We need 2 Br atoms to bond with one Hg atom.