EASY
JEE Main
IMPORTANT
Earn 100

Find (i) the total number of neutrons, and (ii) the total mass of neutrons in 7 mg of C14. (Assume that the mass of a neutron = mass of a hydrogen atom)

Important Questions on Elementary Problems Based on Definition of Mole: The Mole Concept

EASY
JEE Main
IMPORTANT
How many moles are there in 1 m3 of any gas at NTP? Round off the answer up to two decimal places.
EASY
JEE Main
IMPORTANT
3 g of a salt of molecular weight 30 is dissolved in 250 g of water. Calculate the molality of the solution.
EASY
JEE Main
IMPORTANT

Calculate the volume in litres which occupied by 5.25 g of nitrogen at 26°C and 74.2 cm of pressure.

Give the answer within two decimal places.

EASY
JEE Main
IMPORTANT
Find the ratio of the number of molecules contained in 1 g of NH3 and 1g of N2.
HARD
JEE Main
IMPORTANT
How many molecules of CO2 are contained in one liter of air if the volume content of CO2 is 0.03 % at NTP is p×1018. Find out the value of p? 
EASY
JEE Main
IMPORTANT
Is the number of molecules in 1 kg of H2 and 1 kg of O2 the same? What is the ratio of weights of H2 and O2, the mixture of which contains equal number of molecules of each gas? 
EASY
JEE Main
IMPORTANT
The measured density at NTP of a gaseous sample of a compound was found to be 1.78 g/L. What is the weight of 1 mole of the gaseous sample? 
EASY
JEE Main
IMPORTANT

If the concentration of a solution is 2 M. Calculate the number of milli-moles present in 2 litres of the solution.