Question

Yo peeps! :D

Define Atomic mass, Molecular Mass & Moles. Also tell me how to calculate all these.

Thanks in advance!

Answer 1

Answer:

The sum of the no. Of protons and neutrons is called atomic mass.

The molecular mass is defined as the sum of all atoms with their atomic mass present in the molecule

A mole is defined as 6.02214076 × 1023 of some chemical unit, be it atoms, molecules, ions, or others. The mole is a convenient unit to use because of the great number of atoms, molecules, or others in any substance.

Answer 2

$\Huge{\mathsf{Atomic \ Mass}}$

• The mass of a single atom is termed as Atomic Mass

• Earlier,it was measured in "amu" which stands "Atomic Mass Unit" but now it is simply referred as u

• Approximate atomic mass is decided experimentally.

Despite,there's a way to calculate atomic mass mathematically :

$\boxed{ \sf{atomic \: mass \: = no.of \: protons \: + no.of \: neutrons}}$

For example,

Atomic Mass of Hydrogen

A hydrogen atom has one proton and no neutron,this it's atomic mass would be 1

There are some exceptions to the above fact,since :

• Chlorine as an atomic mass of 35.5 u

• Argon has an atomic mass of 40 u

$\Huge{\mathsf{Molecular \ Mass}}$

• Sum of masses of all types of atoms in the molecule.

• Simply put,it's just an addition of masses.

For example,

Mass of NaCl

Molecular mass of sodium is 23u while that of Chlorine is 35.5u

Thus,it's mass would be 58.5 u

$\Huge{\mathsf{Moles}}$

Like quantity of bananas are measured in dozens, quantity of substances like atoms,ions etc. is measured in moles.

Generally as many as 6.023 × 10²³ atoms are taken as 1 mole. In some books,value of one mole is given as 6.022×10²³,this doesn't make much of a difference.

• Moles are abbreviated as mol.

Since,now you are familiar with the concept of moles. Try this :

How many atoms would be 6.023 × 10²³ moles?

Moles can be calculated in following ways :

$\boxed{ \sf{n = \frac{w}{m} }}$

• n is the no.of moles

• w is the given weight

• m is the actual weight in one mole of the substance

Note : i am using the terms mass and weight as the same

For example,

Find the number of moles of calcium in 20g of calcium

Mass of Calcium is 40g

$\sf{n = \frac{20}{40} = } \\ \\ \huge{ \hookrightarrow \: \boxed{\sf{n = 0.5 \: g}}}$