Tag: avogadro's law

Questions Related to avogadro's law

The volume of 2.8 g of $CO$ at $27^0C$ and 0.821 atm pressure is:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. 1.5 litre

  2. 3 litre

  3. 30 litre

  4. 0.3 litre

Show answer
Correct Option: B
Explanation:

Molecular mass of $CO$ = 28. 

Moles of $CO$ present $= \dfrac{2.8}{28}$
 
$V=\dfrac{nRT}{P}=\dfrac{\dfrac{2.8}{28}\times0.0821\times300}{0.821}=3\ litres$

At what temperature will both Celsius and Fahrenheit scales read the same value:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. 100

  2. 180

  3. 40

  4. -40

Show answer
Correct Option: D
Explanation:

We know, $\dfrac{F-180}{212-180}=\dfrac{C-273}{373-273}$


$F=C=-40$

So, the correct option is $D$

An isobaric process is associated with:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. constant temperature

  2. constant volume

  3. constant pressure

  4. small change in enthalpy

Show answer
Correct Option: C
Explanation:

Isobaric process refers to a process taking place at constant pressure.

What could be better than a dozen $(12)$ donuts? How about a baker's dozen $(13)$ of donuts? Another large unit of measurement is known as Avogadro's number $(6.022\times 10^{23})$.
What is TRUE about Avogadro's number?

chemistry quantitative chemistry avogadro hypothesis avogadro's law avogadro law

  1. Avogadro's number is the number of particles in one mole of any element.

  2. The molar mass of a substance will contain $6.022\times 10^{23}$ molecules.

  3. There are $6.022\times 10^{23}g$ of carbon in $12$ mol of $C - 12$.

  4. $6.022\times 10^{23}$ atoms of any element will have the exact same mass regardless of the identity of the element.

Show answer
Correct Option: A
Explanation:

Avagadro constant i.e. $6.023 \times 10^{23}$ particles is the number of constituent particles, usually atoms or molecules, that are contained in the amount of substance given by $1\space mole$. 

In the ideal gas equation, the unit of universal gas constant R is?

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. Mole-atm/K

  2. Litre/mole

  3. Litre-atm/mole.K

  4. erg/K

Show answer
Correct Option: C
Explanation:

In ideal gas equation,


$R=\dfrac{PV}{nT}$ where, 
$P$ is the pressure in 'Atmosphere (atm)'
$V$ is the volume in Litre
$n$ is the number of moles
$T$ is the Temperature in Kelvin (K) 

$ \therefore $Units of $R$= litre.atm/mol.K

A sample of gas has a volume of 0.2 litres measured at 1 atm pressure and $0^oC$. At the same pressure, at $273^oC$, its volume will become:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. 0.1 litre

  2. 0.4 litre

  3. 0.8 litre

  4. 0.6 litre

Show answer
Correct Option: B
Explanation:

According to Charles's law


$\dfrac{V _1}{T _1}=\dfrac{V _2}{T _2}$

$\dfrac{0.2}{273}=\dfrac{V}{546}$

$V=0.4\ litres$

Weight of 22.4 litres of $Cl _2$ gas at STP is:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. 17.25 g

  2. 35.5 g

  3. 73 g

  4. None

Show answer
Correct Option: D
Explanation:

Volume occupied by 1 mole of any gas at STP is 22.4 litres. Therefore, in the question, we are given 1 mole of $Cl _2$ gas, which weigh 71 g.

A gas is initially at $1$ atm pressure. To compress it to $1/4$ th of its initial volume, pressure to be applied is:

chemistry atoms and molecules avogadro hypothesis avogadro's law avogadro law

  1. $1$ atm

  2. $2$ atm

  3. $4$ atm

  4. $1/4$ atm

Show answer
Correct Option: C
Explanation:

According to boyle's law,


$P _1V _1=P _2V _2$

$\Rightarrow 1.V=\frac{V}{4}.P _2$

$\Rightarrow P _2=4\ atm$

Hence, the correct option is $C$

One mole of any substance contains $6.022\times 10^{23}$ atoms/molecules. Number of molecules of $H 2SO _4$ present in $100$mL of $0.02$M $H _2SO _4$ solution is _________?

chemistry quantitative chemistry avogadro hypothesis avogadro's law avogadro law

  1. $12.044\times 10^{20}$ molecules

  2. $6.022\times 10^{23}$ molecules

  3. $1\times 10^{23}$ molecules

  4. $12.044\times 10^{23}$ molecules

Show answer
Correct Option: A
Explanation:

Moles of $H _2SO _4=$ Molarity of $H _2SO _4\times $ Volume of solution $(L)$


$=0.02\times 0.1$


$=2\times 10^{-3}$ moles

No. of $H _2SO _4$ molecules $=2\times 10^{-3}\times 6.022\times 10^{23}=12.044\times 10^{20}$ molecules


Therefore, the correct option is A.

Cations absorb $6.023\times 10^{22}$ electrons for their reduction. How many equivalents of the ion are reduced?

chemistry quantitative chemistry avogadro hypothesis avogadro's law avogadro law

  1. $0.1$

  2. $0.01$

  3. $0.001$

  4. $0.0001$

Show answer
Correct Option: A
Explanation:

1 equivalent of ion absorbs 6. 023 $\times 10^{23}$ electrons 

No. of equivalents reduced = $\dfrac{6.023\times 10^{22}}{6.023 \times  10^{23}}$= 0.1