01 Stoichiometry

Question 1

Mases tvermes desnis

Answer 1

The law of conservation of mass

Question 2

Atom

Answer 2

Smallest particle of an elemnet to show the characteristic properties of that element

Question 3

Native form

Answer 3

Pure elements that are uncombined with other elements in nature

Question 4

Chemical compounds

Answer 4

Substances that exist in combinations with two or more other elements

Question 5

Types of chemical reactions

Answer 5

Combustion

Decomposition

Precipitation

Displacement

Synthesis

Question 6

All concepts of yield

Answer 6

Theoretical yield

Limiting reactant

experimental yield

Percentage yield (experim./theor. x 100%)

Question 7

Atom economy

Answer 7

Atom economy (not yield) shows how much of the reactant ends up as the product (not waste).

The higher the economy, the more effective is the reaction, the less waste

Question 8

Types of mixture

Answer 8

Homogenous: uniform composition

Heterogenous: non-uniform composition

Question 9

Isotope

Answer 9

Isotope is an atom of the same element that has the same number of protons but different number of neutrons

Question 10

Absolute temperature units

Answer 10

K

Question 11

Absolute zero value

Answer 11

0 K

Question 12

Kinetic theory of matter

Answer 12

av. KE of particles is directly related to temperature of the system

Question 13

Diffusion

Answer 13

Diffusion is the process by which particled become evenly distributed as a result of their random movement

The higher the mass of particles, the slower they mix because KE=0.5mv^2 (v - velocity)

Question 14

Relative atomic mass

Answer 14

Notation: Ar

no units!

Question 15

Relative formule mass

Answer 15

Mr

no units!

Question 16

Molar mass

Answer 16

M

g/mol

Question 17

Avogadro’s law

Answer 17

equal volumes of all gases when measured at the same temperature and pressure contain an equal number of particles (occupy the same volume)

1 mol = 22.7 dm^3/mol at STP (T: 0C/ 273 K; P: 100 kPa)

V∝n at constant P and T

Question 18

Avogradro’s constant notation

Answer 18

NA or L

Question 19

Why ideal gas is ideal?

Answer 19

Chemical nature of ideal gas is irrelevant to its volume because the majority of volume in gas is empty space

Question 20

Hydrated salt

Answer 20

Compounds that contain a fixed ratio of water molecules known as water of crystalisation

Opposite: anhydrous salt

Question 21

1 bar =

1 atm =

Answer 21

1 bar = 10^5 kPa

1 atm = 101.325 kPa

Question 22

Relationship between P, V and T

Answer 22

1. V and P

Boyle’s law P∝1/V (pressure depends on volume) at constant T

Formula: P1V1/T1=P2V2/T2

2. V and T

Charle’s law V∝T (volume tepends on temp - KE)

Formula: V/T=constant

3. P and T

P∝T (pressure depends on temp - KE)

Formula: P/T=constant

Question 23

Ideal gas equation

Answer 23

Ideal gas obeys PV=nRT

P at Pa

V at m^3

n at mol

T at K

R - universal gas constant (8.314 J mol^-1 K^-1)

Question 24

ppm concept

Answer 24

ppm - unit of concentration (parts per million)

ppm=mass of component/total mass of solution x 10^6

Question 25

Hard exercise with expression of reaction’s coefficient sum

Answer 25

Question 26

Hard exercise with a graph that represents the relationship between Volume and pressure

Answer 26