Mole Concept

The number of oxygen atoms in $4.4\mathrm{\hspace{0.17em}}\mathrm{g}$ of ${\mathrm{CO}}_2$ is:

The number of oxygen atoms in $4.4$ gram of $\text{C}{\text{O}}_2$ is
(Given that atomic mass $\text{C}$ and $\text{O}$ are $\text{12}$ and $\text{16}$ $\text{g/mol}$ )

The number of atoms in $0.1$ moles of a triatomic gas is:

 $({\mathrm{N}}_{\mathrm{A}}=6.023\times {10}^{23}\text{}{\mathrm{mol}}^{-1})$

$1\hspace{0.17em}\mathrm{cc} {\mathrm{N}}_2\mathrm{O}\mathrm{\hspace{0.17em}}\mathrm{at}\mathrm{\hspace{0.17em}}\mathrm{NTP}$ contains:

Which has maximum number of molecules?

If $N_A$ is Avogadro’s number then number of valence electrons in 4.2 g of nitride ions  $(N^{\mathrm{}3-})is$

1 gm of charcoal adsorbs 100 mL 0.5 M ${\mathrm{CH}}_3\mathrm{COOH}$ to form a monolayer, and thereby the molarity of ${\mathrm{CH}}_3\mathrm{COOH}$ reduces to 0.49. The surface area of the charcoal adsorbed by each molecule of acetic acid. $\left(\text{Surface area of charcoal = 3.01}\times {\text{10}}^2{\text{ m}}^2/\text{gm, Molarity}=\frac{\text{Number of moles}}{\text{1000 mL}}\right)$ will be:

The percentage of copper in a copper$\left(\mathrm{II}\right)$ Salt can be determined by using a thiosulphate titration. $0.305 \mathrm{gm}$ of a copper$\left(\mathrm{II}\right)$ salt was dissolved in water and added to an excess of potassium iodide solution liberating lodine according to the following equation, $2{\mathrm{Cu}}^{2+}\left(\mathrm{aq}\right)+4{\mathrm{I}}^{-}\left(\mathrm{aq}\right)⟶2\mathrm{CuI}\left(\mathrm{s}\right)+{\mathrm{I}}_2\left(\mathrm{aq}\right).$

The iodine liberated required $24.5{ \mathrm{cm}}^3$ of a $0.100$ mole ${\mathrm{dm}}^{-3}$ solution of sodium thiosulphate

$2{\mathrm{S}}_2{\mathrm{O}}_3^{2-}\left(\mathrm{aq}\right)+{\mathrm{I}}_2\left(\mathrm{aq}\right)⟶2{\mathrm{I}}^{-}\left(\mathrm{aq}\right)+{\mathrm{S}}_4{\mathrm{O}}_6^{2-}\left(\mathrm{aq}\right)$

The percentage of copper, by mass in the copper$\left(\mathrm{II}\right)$ salt is.

[Atomic mass of copper $=63.5]$

The volume occupied by one molecule of water$(\mathrm{density}=1 \mathrm{g} {\mathrm{cm}}^{-3})$ is $3\times {10}^{-23} {\mathrm{cm}}^3$.

$600 \mathrm{mL}$ of a mixture of ${\mathrm{O}}_3$ and ${\mathrm{O}}_2$ weighs $1 \mathrm{g}$ at $\mathrm{NTP}$. Calculate the volume of ozone (in mL) in the mixture. (Report your answer in the nearest multiple of 100)

Find the total number of nucleons present in $12 \mathrm{g}$ of ${}^{12}\mathrm{C}$ atoms.

Divide the answer by $1\times {10}^{23}$.

(${\mathrm{N}}_{\mathrm{A}}=6.022\times {10}^{23}$)

Give your answer in two significant figures.

Calculate the mass of $5$ moles of ${\mathrm{CaCO}}_3$ in grams.

How many moles of electrons weigh one kilogram?