Some Basic Concepts Of Chemistry

Question 1

If density is more, particles are

Answer 1

Closely packed

Question 2

Fahrenheit scale from

Answer 2

32° to 212°

Question 3

°F =

Answer 3

9/5(°C) + 32

Question 4

Kelvin formula

Answer 4

°C + 273.15

Question 5

In which scale -ve temp not there

Answer 5

Kelvin

Question 6

1L in cm³

Answer 6

1000

Question 7

4 laws of chemical combination

Answer 7

Compound always contains same elements in same proportion by mass(Definite proportion)
If 2 elements can combine to form > 2 compounds, they do so in a fixed ratio of whole no.s(multiple proportions)
When gases combine , they do so in a simple ratio by volume at STP(Gay lussac)
Equal volumes of all gases have equal no. of molecules at STP(Avogadro)

Question 8

Dalton’s theory

Answer 8

Matter has Indivisible atoms
All atoms have identical properties
They differ in mass
Atoms combine in fixed ratio

Question 9

What could Dalton’s theory not explain?

Answer 9

Law of gaseous volumes
Reason for combing of atoms

Question 10

Molar mass

Answer 10

Mass of 1 mol of substance in gms

Question 11

Empirical formula

Answer 11

Simplest whole no. ratio of atoms in a compound

Question 12

Mass %

Answer 12

(Mass of A/mass of solution)×100

Question 13

Mole fraction of A

Answer 13

No of moles of A/No of moles of solution

Question 14

Molarity

Answer 14

M = No of moles of solute/Volume of solution in L
m1v1 = m2v2

Question 15

Molality

Answer 15

m = no of moles of solute/Mass of solvent in kg

Question 16

What is stoichiometry?

Answer 16

Study of masses of reactants or products

Question 17

chi(a)+chi(b)=

Answer 17

1(molefraction)