Amount Of Substance 2

Question 1

Number of moles

Answer 1

Mass
Number of moles= ———————-
Mass of 1 mole

Question 2

Units of concentraction

Answer 2

Moldm-3

Question 3

Number of given volume in a solution

Answer 3

1000

Question 4

Ideal gas equation

Answer 4

PV = nRT

Pressure = pa
Volume = m3
Gas constant = 8.31 JK-1mol-1
Temperture = k

Question 5

Celsius to kelvin

Answer 5

+273

Question 6

Empirical formula

Answer 6

Simplest whole ratio

Question 7

Molecular formula and then empirical formula

Answer 7

Find the number of units of the empirical formula in the molecular formula, divide the relative molecular mass by the relative mass of the empirical formula

Question 8

Finding concentration by titration

Answer 8

1 fill a burette with the acid of know contraction
2 accurately measure an amount of the alkali using a calibrated pipette
3 add alkali into a conical flask with some universal indictor
4 add the acid drop by drop until the colour changes
5 repeat twice and find the average

Question 9

Atom economy

Answer 9

Mass of desired product
—————————– X100
Total mass of reactants

Question 10

Yield of a chemical reaction

Answer 10

The number of moles
———————————————- x100
Theoretical maximum number of moles

Question 11

Ratio

Answer 11

Ratio

Question 12

Avogardo constant

Answer 12

Avogadro constant is the number of atoms in 12g of a carbon-12

6.022x10(23)

Question 13

1dm-3 to cm3

Answer 13

1000

Question 14

Molecular formula

Answer 14

Tells us the actual number of atoms of each different element that make up then molecules of a compound

Question 15

Water of crystallization

Answer 15

Water occurs inside crystals

Total weight of water in a substance at a given temperature and is mostly present in a definite ratio

Question 16

Percent yield

Answer 16

Actual yield
——————– 100%
Theoretical yield

Question 17

Haber process

Answer 17

Higher temperature gives a fast reaction but decreases the percentage yield of ammonia

450 celerius

Iron catalyst increase rate of reaction

Question 18

Avogadro constant

Answer 18

Actual number of atoms in 1g of hydrogen atoms

6.022x10^23

Question 19

Molar mass

Answer 19

Mass per mole of substance

Question 20

Boyle’s law

Answer 20

Pressure x volume = constant

Question 21

Charles law

Answer 21

Volume / temperature = constant

Question 22

Gay-lussac’s law

Answer 22

(Pressure x volume) / temperature = constant

Question 23

relative atomic mass

Answer 23

the ratio of the average mass of one atom of an element to one twelfth of the mass of an atom of carbon-12

Question 24

relative molecular mass

Answer 24

the ratio of the average mass of one molecule of an element or compound to one twelfth of the mass of an atom of carbon-12.

Question 25

molecular formula

Answer 25

actual number of atoms of each element in a compound