Question

(a)What are cations and anions? Give examples.
(b) Write the formula of the following compounds:
Ammonium chloride
Ferric chloride
(c) Name an element whose atomicity is
Tetra atomic
Monoatomic
(d) How many hydrogen atoms are there in 3 moles of hydrogen?

Answer 1

Hint:One mole of a substance is equal to $6.023\times {{10}^{23}}$ particles of that substance, where the word particle refers to atoms, molecules, and different subatomic particles of the atom. Cations are anions and charged particles are. Atomicity is the number of atoms in a molecule.

Complete step by step answer:
a.When an atom loses electrons and gets oxidized, then the ion form is positively charged and is called the cation. The cation is positively charged due to the reason that the number of protons in the nucleus remain constant but the number of electrons in the valence shell of the atom decreases. When an atom gains electrons then the ion form is negatively charged and is called the anion. This is due to the fact that the number of protons in the nucleus is lesser than the numbers of valence electrons.
b.The formula for Ammonium chloride is \[\text{N}{{\text{H}}_{\text{4}}}\text{Cl}\] while that for ferric chloride is \[\text{FeC}{{\text{l}}_{\text{3}}}\].
c.An example of a tetra atomic molecule is phosphorus ${{\text{P}}_{\text{4}}}$ and monoatomic is neon $\text{Ne}$
d.1 mole of hydrogen = $6.023\times {{10}^{23}}$ atoms of hydrogen
Therefore, 3 moles of hydrogen = $3\times 6.023\times {{10}^{23}}$ atoms of hydrogen = $1.806\times {{10}^{24}}$atoms.

Note:
The atomicity is defined as the number of atoms present in a molecule of the element. Monatomic substances contain one atom, diatomic contains two atoms, and triatomic contains three atoms, and so on. Metals and noble gases are always monoatomic.