# Quiz – Mole Concept and Stoichiometry – 1

QUIZ - Problems / Numericals based on Mole Concept (Atomic Mass/ Molar Mass/ Avogadro number)

Quiz based on -https://freakgenie.com/problems-numericals-based-on-mole-concept/

Mass = Molar mass x Number of moles

Number of particles = Number of moles x Avogadro number

1 / 8

Calculate the number of formula units in 177 g PbCr

${\mathrm{O}}_{4}$

.  (Pb = 206, Cr = 52, O = 16, S = 32,  Avogadro number = No)

Mass = Molar mass x Number of moles

Number of particles = Number of moles x Avogadro number

Note that if it is not mention atom or molecule before mole, it always means one mole of that substance in its natural form.

2 / 8

Calculate the number of molecules in 68.0g of

${\mathrm{NH}}_{3}$

. (N = 14, H = 1, Avogadro number = No)

• Problem based on formula no. – 2
Number of moles = Given number of particles / Avogadro number
Calculation of mole from number of particles and vice – versa.

3 / 8

Calculate the moles of

bromine atoms. (Br = 80).

• Problem based on formula no. – 1
Mass =
Molar mass x Number of moles
Calculation of mass from mole of any fundamental unit like atom, molecule and vice – versa.

4 / 8

Calculate the number of moles in 40.0 g

$B{r}_{2}$

(Br = 80).

• Problem based on formula no. – 3
Number of particles =

Calculation of number of particles from mass and vice – versa.

5 / 8

Calculate the mass of

sodium atoms. (Na = 23).

• Problem based on formula no. – 1
Mass =
Molar mass x Number of moles
Calculation of mass from mole of any fundamental unit like atom, molecule and vice – versa.

6 / 8

Calculate the number of moles in 4Kg

$\mathrm{Na}_{11}^{23}$

(Na = 23).

• Problem based on formula no. – 1
Mass =
Molar mass x Number of moles
Calculation of mass from mole of any fundamental unit like atom, molecule and vice – versa.
• Note that if it is not mention atom or molecule before mole, it always means one mole of that substance in its natural form.

7 / 8

What is the mass of 5 moles of iron?

• Problem based on formula no. – 1
Mass =
Molar mass x Number of moles
Calculation of mass from mole of any fundamental unit like atom, molecule and vice – versa.

8 / 8

How many moles of hydrogen (H2) in 20 g of the gas?