What is the fraction of the mass of water due | vedclass

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

Question

(C) The molar mass of water $(H_2O)$ is $18 \, g/mol$.The mass of one molecule of water is $\frac{18}{N_A} \, g$,where $N_A$ is the Avogadro number.In

Vedclass · Accepted Answer

$\frac{8}{18}$

Vedclass · Answer

(C) The molar mass of water $(H_2O)$ is $18 \, g/mol$.The mass of one molecule of water is $\frac{18}{N_A} \, g$,where $N_A$ is the Avogadro number.In one molecule of water $(H_2O)$,there are $2$ hydrogen atoms and $1$ oxygen atom.Hydrogen $(^1H)$ has $0$ neutrons,while Oxygen $(^{16}O)$ has $8$ neutrons.Therefore,the total number of neutrons in one molecule of water is $8$.The mass of $8$ neutrons is $\frac{8}{N_A} \, g$.The fraction of the mass of water due to neutrons is calculated as: $\frac{	ext{Mass of neutrons}}{	ext{Total mass of water}} = \frac{8/N_A}{18/N_A} = \frac{8}{18}$.

What is the fraction of the mass of water due to neutrons?

Similar Questions

$A$ gas jar contains $1.7 \, g$ of ammonia gas. Calculate the following:
$(i)$ Molar mass of ammonia.
$(ii)$ How many moles of ammonia are present in the gas jar?
$(iii)$ How many molecules of ammonia are present in the sample?

Calculate the molecular masses of $C_2H_4$,$NH_3$ and $CH_3OH$.

Calculate the molecular masses of $H_2$,$O_2$ and $Cl_2$.

$A$ gold sample contains $90\%$ of gold and the rest copper. How many atoms of gold are present in one gram of this sample of gold?

Define formula unit mass of a compound. Calculate the formula unit mass of:
$(a)$ $Na_{2}CO_{3} \cdot 10H_{2}O$
$(b)$ $CuSO_{4}$
(Given atomic mass of $Na = 23 \text{ u}, C = 12 \text{ u}, O = 16 \text{ u}, Cu = 63.5 \text{ u}, S = 32 \text{ u}, H = 1 \text{ u}$)

Vedclass Test Series

Exam Paper Generator

Online Exam Module