How do you calculate the percent composition by mass of each element in $Al(OH_)3$ ?

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Answer 1 · 2018-05-17T15:27:41

$Al = 34.62%$

$O = 61.54%$

$H = 3.85%$

The Percentage Composition by Mass of Each Element is indicated by :-

$"Molar mass of The Element"/"Molar Weight of the Total Compound" xx 100%$

So, The Molar Weight of the Total Compound = ${27 + 3 xx (16 + 1)}$ $g$ $mol^-1$ = $(27 + 51)$ $g$ $mol^-1$ = $78$ $g$ $mol^-1$

So, Percentage Composition of Aluminium = $27/78 xx 100% = 34.62%$ (approx.)

Percentage Composition of Oxygen = $(3 xx 16)/78 xx 100% = 61.54%$ (approx.)

And Percentage Composition of Hydrogen = $(3 xx 1)/78 xx 100% = 3.85%$ (approx.)

How do you calculate the percent composition by mass of each element in Al(OH_)3Al(OH_)3?