Question

How many grams of `K_2CO_3` are needed in order to produce 2.0 mol `K_2O`?

Answer 1

`Mass_(\ K_2CO_3)= 2.8xx10^2 g`

Explanation:

When heated, `K_2CO_3` decomposes according to the following equation:

`K_2CO_3 -> K_2O + CO_2`

The molar mass of `K_2CO_3 = 138.21 \ g. mol^-1`

`2.0 \ mol. K_2O xx (1 \ mol. K_2CO_3)/(1 \ mol. K_2O) xx(138.21 \ g \ K_2CO_3) / (1 \ mol. K_2CO_3)`

`2.0 \cancel( mol. K_2O) xx ( 1 \color(red) cancel( mol. K_2CO_3))/(1 \ cancel(mol. K_2O)) xx(138.21 \ g \ K_2CO_3) / (1 color(red) cancel(\ mol. K_2CO_3) )`

`= 2.8xx10^2 g`