Question

20.a. Define Valency. Find the Valency of oxygen and aluminum
b. Which one will have more number of atoms 100 g of N2 or 100 g of
NH3
c. Calculate the number of moles present in 50 g of calcium
carbonate.​

Answer 1

Define Valency

It is the ability of an atom to gain or lose electron in order to achieve the noble gas configuration. It refers to the ability of an element to combine with other element.

Valency of Oxygen and Aluminium

the valency of oxygen is 2

the valency of aluminium is 3.

Which one will have more number of atoms 100 g of N2 or 100 g of NH3

100g of N2 or 100g of NH3. =4.2×1024 atoms. Thus, 100g of NH3 has more number of atoms.

Calculate the number of moles present in 50 g of calcium carbonate.

50g of caco3=1÷100×50=0.5 moles

$bts (◍•ᴗ•◍)❤ exo$

Answer 2

Answer is o.5 moles.....