A compound has the following composition by w | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(D) To find the empirical formula,we calculate the moles of each element by dividing the percentage by its atomic mass:$Na: \frac{18.60}{23} = 0.808 \

Vedclass · Accepted Answer

$Na_2S_2O_3 \cdot 5H_2O$

Vedclass · Answer

(D) To find the empirical formula,we calculate the moles of each element by dividing the percentage by its atomic mass:$Na: \frac{18.60}{23} = 0.808 \approx 0.8$$S: \frac{25.80}{32} = 0.806 \approx 0.8$$H: \frac{4.02}{1} = 4.02$$O: \frac{51.58}{16} = 3.22$Dividing by the smallest mole value $(0.8)$:$Na: \frac{0.8}{0.8} = 1$$S: \frac{0.8}{0.8} = 1$$H: \frac{4.02}{0.8} \approx 5$$O: \frac{3.22}{0.8} \approx 4$The empirical formula is $NaSH_5O_4$. Since all $H$ atoms are in water of crystallisation $(H_2O)$,$5$ atoms of $H$ correspond to $2.5$ molecules of $H_2O$. To get whole numbers,we multiply by $2$,giving $Na_2S_2H_{10}O_8$,which is $Na_2S_2O_3 \cdot 5H_2O$.

$A$ compound has the following composition by weight: $Na = 18.60 \%$,$S = 25.80 \%$,$H = 4.02 \%$,and $O = 51.58 \%$. Assuming that all the hydrogen atoms in the compound are part of water of crystallisation,the correct molecular formula of the compound is:

Similar Questions

Calculate the mass percent of different elements present in sodium sulphate $(Na_{2}SO_{4})$.

The empirical formula of a compound is $C_2H_5O$ and its vapour density is $45$. What is the molecular formula of the compound?

The weight percentage of $C$ and $H$ in a hydrocarbon is in the ratio of $4: 1$. What is its empirical formula?

An organic compound contains $C$,$H$ and $S$. The minimum molecular weight of the compound containing $8\%$ sulphur is........$g\,mol^{-1}$ (atomic weight of $S = 32\,amu$)

An organic compound containing carbon and hydrogen has an empirical formula of $CH_2$. The mass of $1 \ L$ of this organic gas is equal to the mass of $1 \ L$ of $N_2$ gas at the same temperature and pressure. What is the molecular formula of the organic gas?

Vedclass Test Series

Exam Paper Generator

Online Exam Module