Some basic

Concepts

Of chemistry

ANSWERS ARE ON SECOND PAGE

Q.1- Define 1 u?

Q.2- What is the relation between Celsius and Fahrenheit?

Q.3- What is a S.I unit?

Q.4- What is the Atomic Mass of Iron?

Q.5- What is a Mole?

Q.6- What is a relative Atomic Mass?

Q.7- How can we find Mass % of a Solute present in a Solution?

Q.8- What is Mole Fraction?

Q.9- What is Molarity?

Q.10- What is Molality?

Q.11- what is Normality?

ANSWERS

(1) 1 u is defined as the 1/12 of the mass of C-12 isotope. 1 u =1.66×10−24g

(2) ℉= 9/5(℃) +32(3) The International System of units is known as S.I unit.(4) 55.85 gram/mole(5) The mole is the unit of the amount of a substance which tells us the

atoms, molecules or ions of the substance. It also represents gram molecular or gram atomic mass. 1 mole =6.022×1023

(6) Average atomic mass is called relative Atomic Mass.

(7) Mass % of a Solute present in a Solution = mass of solutemassof solution ×100.

(8) Mole Fraction =numberof moles of substanceAnumber of molesof solution

(9) Molarity =numberof moles of solutevolumeof solution∈litres

(10) Molality = numberof moles of solutemassof solvent∈kg