Question

a sample of sodium bicarbonate is known to contain some impurities. It is found that Na makes up 18.00% of the entire mass of the sample. All of the Na comes from the NaHCO3 compound. Find the mass percent of NaHCO3 in the sample

Answer 1

Answer : The mass percent of
`NaHCO_3` in the sample is, 65.7 %

Explanation :

As we are given that Na makes up 18.00% of the entire mass of the sample.

First we have to calculate the mass percent of Na in
`NaHCO_3`.

`\text{Mass percent of Na}=\frac{\text{Mass of Na}}{\text{Mass of }NaHCO_3}* 100`

Mass of Na = 23 g

Mass of
`NaHCO_3` = 84 g

Putting values in above equation, we get:

`\text{Mass percent of Na}=(23g)/(84g)* 100=27.4\%`

Now we have to calculate the mass percent of
`NaHCO_3` in the sample.

As, 27.4 % amount of Na present in 100 %
`NaHCO_3`

So, 18 % amount of Na present in
`(18)/(27.4)* 100\%=65.7\%`
`NaHCO_3`

Therefore, the mass percent of
`NaHCO_3` in the sample is, 65.7 %