1i & 2f Key Points

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Anomalous results

异常值

​Sometimes you will see one result that is clearly wrong

because it falls well away from the pattern of the others.

This is called an anomalous result. You might be

asked to explain what might have caused it. When you

are drawing your straight line or curve, you ignore the

anomalous point completely.

Anomalous results

具体问题具体分析

Your explanation should be as precise as you can make it. Decide whether the point is too high or too low on the graph, then try to think of an experimental reason why that might have happened. It isn’t enough to say simply that ‘wrong measurements were taken or human error’,

you have to be much more specific, for example ‘too much calcium carbonate was added by mistake, and that produced more carbon dioxide than expected’.

Open Ended

So, What is anomalous result?

Multiple Choice

When you draw the best fit line/curve, should the anomalous point be included?

• No

• Yes

Describing the relationships shown by a graph

描述关系

• directly proportional to

• proportional to

• inversely proportional to

• linear relationship

• positive/negative correlation

The words proportional and directly proportional mean the same thing

--> y = kx

-->graph: a straight line +

passing through the origin.

​Some text here about the topic of discussion.

proportion

If you just say that ‘as the mass

of calcium carbonate increases, the volume of carbon

dioxide increases’, that isn’t precise enough, and you may

not get the full mark. That faulty statement could equally

well describe a curve.

​Some text here about the topic of discussion.

proportion

If a straight line does not pass through the origin, you should say there is a linear relationship between the two variables.

线性关系

Linear relationship

positive correlation

negative correlation

if it is a straight line and

positive gradient --》positive and linear correlation

negative gradient --》negative and linear correlation

线性关系

Linear relationship

Multiple Choice

A is directly proportional to the square of B

• $$A\propto B$$ 

• $$A\propto B^2$$

• $$A\propto\sqrt{B}$$

• $$A\propto B^3$$

Multiple Choice

y is directly proportional to x. When x= 2, y = 8. Which equation represents this situation?

• $$y=4x$$

• $$y=0.25x$$

• $$y=\frac{4}{x}$$

• $$y=\frac{1}{4x}$$

Multiple Choice

Which of the following represents direct variation?

• y = kx

• y = k/x

• y = x/k

• y = mx + b

Multiple Choice

Is this a direct variation?
y=2x

• yes

• no

Fill in the Blanks

Multiple Choice

What type of correlation does this graph have?

• positive

• negative

• none

• all of the above

Multiple Choice

Which scatterplot suggests a linear association?

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Open Ended

What is the difference between ion and electron?

Electrons are negatively charged micro particles and ions are either negatively or positively charged molecules or atoms.

e.g. Na loses 1 electron and become a positive ion

ion v.s. electron

Multiple Choice

When an element gives up electrons...

• it becomes an anion

• it becomes a cation

• it becomes an ion

• Good things happen

Multiple Choice

When an element gains electrons...

• it becomes an anion

• it becomes a cation

• it becomes an ion

• Bad things happen

Multiple Choice

If you gain 1 electron, your charge is ...

• 1⁺

• 1^-

• Neutral

Multiple Choice

If you lose 2 electrons, your charge is ...

• 2⁺

• 1^-

• 2^-

Multiple Choice

X atom has 12 protons. what is the electron arrangement of atom X?

• 2.8

• 2.8.8

• 2.8.2

• 2.10

Multiple Choice

What is the electron arrangement of Cl-

• 2,8,7

• 2,8,6

• 2,7

• 2,8,8

Match

Match the following

• Mg

• O

• $$O^{2-}$$  

• Mn

• Hg

Magnesium

Oxygen

Oxide

Manganese

Mercury

• Magnesium

• Oxygen

• Oxide

• Manganese

• Mercury

Multiple Choice

Why do ionic compounds NOT conduct electricity when they are in their solid state?

• Their ions are free to move.

• Their ions are held in fixed positions.

• Their electrons are free to move

• Their electrons are held in a fixed state

Multiple Choice

Why do ionic compounds have high melting and boiling points?

• Their ions are free to move.

• Their ions are held in fixed positions.

• They have many strong bonds which require a large amount of heat energy to overcome these strong bonds.

• They have weak bonds which require a little amount of heat energy to overcome these weak bonds.

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Physical Properties

• Properties that can be observed without changing the identity of the substance.

Chemical Properties

Chemical properties describes how a substance reacts to other substances.

The question to ask!

Are these properties determined without changing the identity of the substance?

Multiple Choice

Water (H₂O) freezes at zero degrees celsius. Is freezing an example physical or chemical property?

• physical property

• chemical property

Multiple Choice

An iron nail is left outside on the porch exposed and rusts. Is rusting an example of a physical or chemical property?

• physical property

• chemical property

Multiple Choice

Is burning wood in a campfire a physical or chemical change?

• physical change

• chemical change

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

E.G. the decomposition of hydrogen peroxide

How you would find out how changing the concentration of the hydrogen peroxide affects the rate?

modifying experiments

Open Ended

How you would find out how changing the

concentration of the hydrogen peroxide affects the rate? (Remember: to be precise!)

modifying experiments

Whatever it is that you are changing, that must be

the only thing which changes from one experiment

to the next.

unchanged:

• the concentration of every other solution involved

• The total volume

• The temperature

• The mass of any solid, and so must its size (powder, small lumps, big lumps and so on)

Multiple Choice

The independent variable is the ONE thing you _____.

• change

• keep the same

• experiment with

• investigate

Multiple Choice

The variables in an experiment that stay the same are the - 

• IV

• DV

• Controll variables

Multiple Choice

The variable that is measured. It is the result of the experiment.

• Controlled Variable

• Dependent Variable

• Independent Variable

Multiple Choice

Why is it important to have only one independent variable and to control the other variables when performing science experiments?

• So you can tell which factor is causing the change in the experiment and get more accurate results

• It does not matter, you can have as many independent variables as you want.

• None of these answers are correct

Multiple Choice

One chicken is injected with a growth hormone while another chicken is not injected with a growth hormone. After one year, both chickens are weighed. What is the independent variable?

• If a chicken was injected with a growth hormone or not

• The weight of the chicken

• The type of chicken

Multiple Choice

One chicken is injected with a growth hormone while another chicken is not injected with a growth hormone. After one year, both chickens are weighed. What is the dependent variable?

• If the chicken was injected with a growth hormone or not

• The weight of the chicken

• The type of chicken

Multiple Choice

What is the CONSTANT VARIABLE (same) in this picture?

• type of the plant

• weight of the plant

• price of the plant

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Concentration

• measure of the amount of solute in a given amount of solvent or solution

• 2 ways to measure

• concentration = mass / volume (g/dm3)

• concentration = mole / volume (mol/dm3)

Match

Match the following

• 1 m3

• 1 dm3

• 1 cm3

• 1 dm3

• 1 cm3

1000 L

1 L

1 ml

1000 cm3

0.001 dm3

• 1000 L

• 1 L

• 1 ml

• 1000 cm3

• 0.001 dm3

Molarity

• number of moles of solute in one liter of solution

• How to make

• 1. Determine desired molarity i.e. .5 M, 1 M

• 2. determine the mass needed by converting mol to gram

• 3. dissolve in less solvent than 1 L

• 4. Bring total solution to 1 L

Multiple Choice

What is the molarity of 3 mole of hydrochloric acid in 3 L of water. 

• 3

• 1

• 6

• 9

Multiple Choice

What is the molarity of a 0.5L sample of a solution that contains 60.0 g of sodium hydroxide (NaOH)

(Na =23, H=1, O=16)

• 0.8 M

• 1.5M

• 3.0M

• 6.0M

Multiple Choice

How many moles of NaCl are present in a solution with a molarity of 8.59 M and a volume of 125 mL?

• 1074 mol

• 0.069 mol

• 1.07 mol

• 62.7 mol

Multiple Choice

A beaker contain 795 mL of 0.35M of Na₂SO₄ solution. Calculate the mass of Na₂SO₄.

(Na =23, S=32, O=16)

• 39.55 g

• 40.00 g

• 39.05 g

• 39.5 g

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Consider this reaction,

CuSO₄ (aq) + 2NaOH (aq) --> Na₂SO₄ (aq) + Cu(OH)₂ (s)

Multiple Choice

Identify the spectator ions below:

Cu²⁺ (aq) + SO₄^2- (aq) + 2 Na⁺ (aq) + 2 OH^- (aq) --> 2 Na⁺ (aq) + SO₄^2- (aq) + Cu(OH)₂ (s)

• Cu²⁺ and OH^-

• Cu²⁺ and SO₄^2-

• Na⁺ and OH^-

• Na⁺ and SO₄^2-

Multiple Choice

CuSO₄ (aq) + 2NaOH (aq) --> Na₂SO₄ (aq) + Cu(OH)₂ (s)

The final ionic equation for the equation above is,

• Cu²⁺ (aq) + 2 OH^- (aq) --> Cu(OH)₂ (s)

• SO₄^2- (aq) + 2Na⁺ (aq) --> Na₂SO₄ (aq)

• CuSO₄ (aq) --> Cu²⁺ (aq) + SO₄^2- (aq)

• NaOH (aq) --> Na⁺ (aq) + OH^- (aq)

Multiple Choice

Which one are the spectator ions?

2Na⁺ (aq) + 2Cl^- (aq) + Pb²⁺ (aq) + 2NO₃^- (aq)→ 2Na⁺ (aq) + 2NO₃^- (aq) + PbCl₂ (s)

• Na⁺ and NO₃^-

• Na⁺ and Cl^-

• Pb²⁺ and NO₃^-

• Pb²⁺ and Cl^-

Multiple Choice

2Na⁺ (aq) + 2Cl^- (aq) + Pb²⁺ (aq) + 2NO₃^- (aq)→ 2Na⁺ (aq) + 2NO₃^- (aq) + PbCl₂ (s)

The final ionic equation for the above is

• Na⁺ (aq) + NO₃^- (aq) --> NaNO₃ (aq)

• 2Cl^- (aq) + Pb²⁺ (aq) → PbCl₂ (s)

• Pb²⁺ (aq) + NO₃^- (aq) --> Pb(NO₃)₂ (aq)

• molarity

• concentration

• ionic equation

• neutralisation

2f acid and base

• Anomalous result

• directly proportional

• ion v.s. electron

• physical properties

• control variable

1I ELECTROLYSIS TEST

Key terms

Some text here about the topic of discussion

Drag and Drop

Neutralisation reaction is a chemical reaction in which

acids react with ​

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​ (e.g. MgO) or ​

Placeholder

(e.g. NaOH) to produce ​

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.

Drag these tiles and drop them in the correct blank above

bases

alkalis

salt

metal

nonmetal

acid

alkaline