Chemistry

Question 1

Example of manipulated variable

Answer 1

= What you are testing (most experiments only have one variable)

EX: The experiment is how much water is needed in order for a plant to grow. The MANIPULATED variable would be the amount of water.

Question 2

Example of the responding variable

Answer 2

= The results from the experiment (dependent on the manipulated variable)

EX: Experiment of plants growth. The RESPONDING variable would be how much the plant grows which was dependent on how much water was givin to the plant.

Question 3

Example of a controlled variable

Answer 3

= What is kept the same throughout th eexperiment.

Ex: Experiment on how much a plant grows based on the amount of water given. The CONTROLLED variable would be if the soil was th esame throughout the whole experiment.

Question 4

Two types of testing groups are

Answer 4

1) Experimental = The experiment

2) Control group = For comparison to measure the change compared to the normal group (the normal group)

Question 5

Two types of data are

Answer 5

1) Qualitative = Observed with natural senses (you can observe ht equality of something)

2) Quantitative = Involves actual measurements (quality doesnt matter only the exact quantity)

Ex: determining heigh with a ruler compared to observing its tall.

Question 6

Acids (properties / traits)

Answer 6

• Have a pH less than 7
• Corrosive
• Conductive
• Taste sour
• Reacts with metals
• Turns blue litmus paper red

Question 7

Bases (properties / traits)

Answer 7

• Have a pH higher than 7
• Turns red litmus paper blue
• Tastes bitter
• Conductive
• does not react with metals
• Corrosive

Question 8

Difference between neutral ionic compounds and molecular compounds

Answer 8

Neutral ionic compounds = Metal + Non-metal and are conductive but are not corrosive and does NOT react with metals

Neutral molecular compounds = Non-metal + Non-metal and are not corrosive, conductive, are reactive to metals.

Question 9

Dissociation

Answer 9

When molecules separate and turn into ions

Question 10

Ionization

Answer 10

The formation of ions

Question 11

Difference between concentration and strength

Answer 11

Concentration = amount of substance in a solution

Strength = Dependent on the amount of dissociation

Question 12

Bronsted and Lowry’s Proton donor summary

Answer 12

1) acids donate a proton -> then becomes a conjugate base

2) Bases accept a proton -> then becomes a conjugate acid

Question 13

Finding the pH on a basic calculator and scientific calculator

Answer 13

• On a scientific calculator put the H3O+ in (2.5 x 10) an dpress =
• On a basic calculator put concentration in first, press EXP button, then put exponent in, then press LOG

Question 14

Finding the H3O+ on a scientific and basic calculator

Answer 14

• On a scientific put 10 to the power of the negative pH given then press =
• on basic put in 10, then the XY button, then =, then move decimal so you have the same amount of the other numbers given.

Question 15

pH colour indicators

Answer 15

If the pH is less than the lower number it will show as the first colour listed.

If the pH is between the colours listed it will show as a mix of the two colours listed

If the pH is higher than the largest number listed it will show as the last colour.

Question 16

Titrations / and summery of steps

Answer 16

Used to determine unknown concentration of solution by adding measurements of a known solution until a reaction happens at the endpoint (color change) (usually base being added to an acid)

1) Add known solution (base) to burette and record initial volume.

2) use pipette to fill erlenmeyer flask with unknown solution (acid)

3) Add the indicator in with the acid

4) Titrate by adding known solution to unknown till color change / neutralization / endpoint occurs then record final volume.

Question 17

Buffers

Answer 17

Substance that resists change in the pH (H3O ions) when exposed to acids or bases

Question 18

Acid rain description

Answer 18

• pH less than 5.6
• Both wet and dry
• Formed by Sulphur oxides and Nitrogen oxides (SOX’s and NOX’s)
  I-> which are both products from burning
  coal and other fuels as well as manmade
  events

Question 19

SOX (sources natural and anthropogenic)

Answer 19

Natural = Volcanic and Hot springs (So Hot)

Anthropogenic (manmade) = Burning fossil fuels and refining crude oils, oil sand, and metals

Question 20

NOX ( sources natural and anthropogenic)

Answer 20

Natural = Forest fires (No water to put out flames so temp fie and forest fires)

Anthropogenic = High temperature combustion in cars and home furnaces

Question 21

Environmental effects of acid rain

Answer 21

• Changes in soil pH
• Washes away soil nutrients
• Leaching of fertilizers and metals ions into the water
• Lethal conditions for aquatic populations impacting the food chain.
• Defoliation of plants

Question 22

Social effects of acid rain

Answer 22

• Corrosion of buildings, monuments and statues
• Dry deposition and increased rates of asthma and bronchiolitis

Question 23

How to reduce and recover from acid rain

Answer 23

1) Electrostatic precipitator = Collects particulates from emissions

2) Scrubbers = Removes Sulphur dioxide from combustion of coal by adding a weak base

3) Catalytic converters = Reduces Nitrogen oxides by converting them to Carbon dioxide and H2O

4) Liming of Lakes = Adding calcium carbonate to lakes with granite to help neutralize the acidified water

Question 24

Photochemical smog

Answer 24

Smog results emissions such as NOX, particulars, HwS and tropospheric ozone (ground level ozone)
-> Which al cause irritation to eyes, throat, nose, and lungs