Broderick's Chapter 1 Stoichiometry

Question 1

Explain the three states of matter ? include distance, arrangement of particles, shape and volume, movement of particles, energy of particles, speed and forces of attraction between particles.

Answer 1

Solids - close together, regular, fixed shape and volume, vibration, slowest, lowest strongest.

Liquids - close but further apart from solids, random, no fixed shape, fixed volume, move around each other, faster, higher, weaker

Gases - particles far apart, random, no fixed shape, no fixed volume, move around in all directions, fastest, highest, weakest.

Question 2

Explain the changes of state

Answer 2

Solid to liquid - melting 
liquid to gas -  evaporation / boiling 
gas to liquid  - condensation 
liquid to solid - freezing 
solid to gas - sublimation

Question 3

Difference between boiling and evaporation

Answer 3

Boiling is throughout liquid (only at boiling point)

Evaporation only happen on the surface of the liquid ( can happen any temp )

Question 4

Define element, compound and mixture and atom

Answer 4

element - pure substance that only contains only one type of atom

atom - smallest part of an element that can still be recognized as that element

compound - a pure substance formed by chemically bonding two or more elements

mixture - contains two or more substance mixed together

Question 5

Define homogenous mixture and heterogeneous mixture

Answer 5

homogeneous mixture - same composition throughout the mixture and therefore consists of only one phase

heterogenous mixture - do not have uniform compositions and consists of different phases

Question 6

Process that separates homogeneous mixture and heterogeneous mixtures

Answer 6

Homogenous can be separated by physical means - simple distillation and evaporation

Heterogeneous can be separated by mechanical means - filtration

Question 7

What is the colour change of phenolphthalein in a titration experiment

Answer 7

colourless in acidic

pink in alkali

Question 8

Colour change of methyl orange in a titration experiment

Answer 8

red in acidic solutions

yellow in alkali solutions

Question 9

What conditions do gasses deviate from ideal behaviour ?

Answer 9

high pressure and low temperature

At high pressures, the particles have a finite volume

At low temperatures, the intermolecular forces (or attractive forces) overcome the low kinetic energy of the particles.

Question 10

The gas laws

Answer 10

Boyle’s law (constant temperature) = double pressure = halve volume

Charle’s law (constant pressure) = double temperature (kelvin) = double volume