Q5 of 24 Page 165

Calculate the gram molecular mass of water from the values of gram atomic mass of Hydrogen and of Oxygen.

Gram atomic mass of Hydrogen = 1 g


Gram atomic mass of Oxygen = 16 g

If the molecular mass of a given substance is expressed in grams, it is known as gram molecular mass of that substance. Molecular mass is the sum of the atomic masses of all the atoms present in one molecule of the substance.


One molecule of water is H2O, which contains 2 hydrogen and one oxygen atoms. So, molecular mass is sum of atomic masses of hydrogen and oxygen atoms.






Gram molecular mass of water is 18g.

More from this chapter

All 24 →
3

Gram molecular mass of Oxygen is 32 g. Density of Oxygen is 1.429 g/litre. Find the gram molar volume of Oxygen.

 4

‘Cl’ represents Chlorine atom, ‘Cl2’ represents Chlorine molecule.

List out any two differences between atoms and molecules.

 6

One mole of any substance contains 6.023 x 1023particles.

If 3.0115 x 1023 particles are present in CO2, find the number of moles.

 7

_________ have equal number of neutrons.

i) Isobars ii) Isotones


iii) Isotopes iv) Mass Numbers