# How many grams are contained in 0.50 mol of each compound: HCl, Na2SO4, C2H2, and Al(OH)3?

## Question:

How many grams are contained in 0.50 mol of each compound: {eq}HCl, Na_2SO_4, C_2H_2, {/eq} and {eq}Al(OH)_3 {/eq}?

## Number of Moles:

There are seven basic units in the international unit system and one of them is the mole. It is used to express the amount of the substance. The unit of Mole is mol. The mole of a substance is defined as the mass of the substance divided by the molar mass of the substance.

Given,

Number of moles of each compound = 0.50 mol

Formula used is:

{eq}\rm Number\, of \,moles=\dfrac{Mass\,of\,compound}{Molar\,mass} \\Mass=Number\, of \,moles\times Molar\,mass {/eq}

(a) {eq}HCl {/eq}

• Molar mass of HCl = 36.5 g/mol

Mass of HCl present in 0.50 mol = {eq}0.50\,mol\times 36.5\,g\,mol^{-1}=18.25\,g {/eq}

(b) {eq}Na_2SO_4 {/eq}

• Molar mass of sodium sulfate = 142 g/mol

Mass of sodium sulfate present in 0.50 mol = {eq}0.50\,mol\times 142\,g\,mol^{-1}=71\,g {/eq}

(c) {eq}C_2H_2 {/eq}

• Molar mass of ethyne = 26 g/mol

Mass of ethyne present in 0.50 mol = {eq}0.50\,mol\times 26\,g\,mol^{-1}=13.0\,g {/eq}

(d) {eq}Al(OH)_3 {/eq}

• Molar mass of aluminum hydroxide = 78 g/mol

Mass of aluminum hydroxide present in 0.50 mol = {eq}0.50\,mol\times 78\,g\,mol^{-1}=39.0\,g {/eq}