Question

Calculate the number of equivalents in each of the following:

a.$1{\text{mole ofMg}}^{2+}$

b.${\text{0.5mole ofH}}^{+}$

c.${\text{4molesofCl}}^{-}$

d.${\text{2molesofFe}}^{3+}$

Short answer

(part a) The number of equivalents in${\text{1moleofMg}}^{2+}\text{=2eq}$

(part b) The number of equivalents in ${\text{0.5moleofH}}^{+}\text{=0.5eq}$

(part c) The number of equivalents in ${\text{4molesofCl}}^{-}\text{=4eq}$

(part d) The number of equivalents in${\text{2molesofFe}}^{3+}\text{=6eq}$

Step-by-step solution

Introduction (part a).

In a chemical process, an equivalent has been the quantity of one material that people react to (or is equivalent to) an arbitrarily defined quantity of another compound. The mass of an equivalent is equivalent to its weight.

Given Information (part a).

Given:

$1{\text{mole ofMg}}^{2+}$

Explanation (part a). 

To compute the value of equivalents.

Each mole has two equivalents for such an ion with a charge of $2+.$Thus the,

${\text{1moleofMg}}^{2+}\text{=2eq}$

Given Information (part b). 

Given:

${\text{0.5mole ofH}}^{+}$

Explanation (part b). 

To compute the value of equivalents.

Each mole contains a single equivalent for just an ion with a charge of $+.$Therefore,

${\text{0.5moleofH}}^{+}\text{=0.5eq}$

Given Information (part c). 

Given:

${\text{4molesofCl}}^{-}$

Explanation (part c). 

To compute the value of equivalents.

Every mole uses a single equivalent for an ion with a charge of $-.$Thus,

${\text{4molesofCl}}^{-}\text{=4eq}$

Given Information (part d). 

Given:

${\text{2molesofFe}}^{3+}$

Explanation (part d).

To compute the value of equivalents.

There's really one equivalent with each mole of an ion with a charge of $-.$Consequently,

${\text{2molesofFe}}^{3+}\text{=6eq}$