Chemistry: sept 11 Flashcards

1
Q

How many decimal points should you measure a burette too

A

2 decimal points

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the boiling point of water

A

100 degrees celsius

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What element has the atomic number 20

A

Calcium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Define relative atomic mass

A

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

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What term is used to describe an oxide that reacts with acids and alkalis

A

Amphoteric

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What should a dot and cross diagram have

A

dots and crosses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Mole formula

A

N = m/mr

moles = mass/molecular mass

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is a spatula used for

A

Spatulas are used to transport and distribute dry chemical compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

describe ionic compounds

A

It conducts electricity when dissolved in water
It has a high melting point due to strong attractive forces between ions
the ionic bonds are formed between metallic and non metallic elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

is this statement about oxides correct: Magnesium oxide reacts with nitric acid to make a salt

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

why are mixtures filtered

A

To remove the excess filtrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Properties of ammonia (NH3)

A

colourless

less dense than air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

uses of caustic soda (sodium hydroxide)

A

Drain cleaner

Fertiliser

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Calcium carbonate used for (CaCO3)

A

Kitchen benches (when its marble)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

how to make concrete

A

CaCO3 is broken down to CaO + CO2 which equals Ca(OH)2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

dissolving

A

The process in which solvent molecules such as water surround solute particles such as ions
(like those in salt) or molecules (like those in sugar)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Are all nitrates, sodium, potassium and ammonium salts are soluble.

A

yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What chlorides, bromides and iodides are not soluble

A

Pb2+, Cu+ and Ag+ are not soluble

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how many flourides are soluble

A

All of them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What carbonates are soluble

A

The carbonates of alkali metals are soluble

The rest aren’t

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What sulphates are soluble

A

Most sulphates are soluble, Ca2+ and Pb2+ are not Ag+

and Ba2+ are slightly soluble.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

how to perform a flame test

A
  1. Dip a clean flame test loop in concentrated hydrochloric acid.
  2. Hold the flame test loop at the edge of a roaring bunsen burner flame and ensure the flame does not
    change colour. If it does dip in acid again and repeat.
  3. Dip the wire in the solid being testing picking up a few crystals and hold it at the edge of the roaring
    Bunsen flame and observe the changed colour of the flame, and decide which metal it indicates.
  4. Clean the loop in acid and rinse with water, then repeat steps 1 to 3 with a new sample.
23
Q

Ion’s reaction in flames

A

Lithium (Li+) Red flame
Sodium (Na+) Orange/Yellow flame
Potassium (K+) Lilac flame
Copper(II) (Cu2+) Blue/Green flame

24
Q

Non metal oxides are

A

acids

25
Q

Metal oxide + acid =

A

salt + water

26
Q

Metal oxides are

A

bases

27
Q

What does hydrated mean

A

it has water in it

28
Q

Aqueous ammonia is added to a solution of a salt. A white precipitate is formed which dissolves in an
excess of aqueous ammonia. Which metal is in the salt?

A

Zinc

29
Q

Two aqueous solutions, X and Y, are mixed together. What pair would not give
a white precipitate?

A

Magnesium nitrate and sodium sulphate

30
Q

Dilute hydrochloric acid was added to a tube containing a unknown powder. There was a vigorous
reaction and a gas was produced which turned lime water cloudy. After the reaction stopped, excess
aqueous sodium hydroxide was added to the tube and a green gelatinous precipitate was formed.
What was the unknown powder.

A

FeCO3

31
Q

When aqueous ammonium chloride was heated with aqueous Y, a gas which turned universal
indicator paper blue was evolved. Which ion must have been present in Y?

A

OH-

32
Q

What is a fuel

A

something with stored chemical energy

33
Q

What does exothermic mean

A

gives out heat

34
Q

What does delta H =

A

enthalpy change

35
Q

What is the symbol for delta

A

36
Q

What does EA mean

A

Activation energy

37
Q

why do you need activation energy

A

to make stuff react

38
Q

What is the unit of Enthalpy change

A

KJmol-1

39
Q

Formula for amount of energy

A

energy (j) = heat capacity x mass x change in temp

40
Q

The collision theory

A

If two particles hit each other at high energy in the right orientation you get a reaction

41
Q

How does temperature affect rate of reaction

A

High temperature increases frequency and success

42
Q

How does surface area affect rate of reaction

A

larger surface area increases frequency of collisions

43
Q

How does concentration affect rate of reaction

A

Higher concentration increases frequency of collisions

44
Q

How does a catalyst affect rate of reaction

A

Increase a rate of reaction without being consumed, increases the success of collisions

45
Q

what increases frequency of collisions

A

Temperature
Surface area
Concentration
Pressure

46
Q

What increases success of collisions

A

Temperature

catalyst

47
Q

How to speed reaction

A

warming it
Increasing pressure (only gas)
increasing concentration
Using a catalyst

48
Q

How does change in concentration affect equilibrium

A

If the concentration of one side of the equation is lowered for some reason, then the equation will shift so more is made to replace that which is lost. If the concentration of one side is increased, then that side will react quickly to get rid of the excess and restore the equilibrium to what it was.

49
Q

how does change in temperature affect equilibrium

A

A change in temperature will affect the equilibrium depending on which direction on the equilibrium
is more exothermic. Le Chatelier’s principle applies to a change in temperature because the reversible
reaction would be exothermic in one direction and endothermic in the other, so an increase in
temperature would mean that the endothermic reaction would be favoured and vice versa. If the
temperature is raised, the equilibrium would shift so the less exothermic reaction would occur more
and so the temperature would try to fall. If the temperature were lowered, then the equilibrium would
shift so the more exothermic reaction would occur more and create ore of the substance at that end of
the equation.

50
Q

How does change in pressure affect equilibrium

A

If the equation is off gasses and has different numbers of molecules on both sides, the equilibrium would shift so the pressure could be restored back to what it was.

51
Q

How does adding a catalyst affect equilibrium

A

The addition of a catalyst does not change the concentrations of reactants or products. It does speed up the reaction rate in both forward and reverse directions and allows the system to reach equilibrium
more rapidly.

52
Q

what does homogeneous mean

A

A substance is homogeneous if its composition is identical wherever you sample it - it has uniform composition and properties throughout.

53
Q

what does dynamic mean

A

In chemistry, and in physics, a dynamic equilibrium exists once a reversible reaction occurs. Substances transition between the reactants and products at equal rates, meaning there is no net change.

54
Q

what does equilibrium mean

A

Chemical equilibrium, condition in the course of a reversible chemical reaction in which no net change in the amounts of reactants and products occurs. A reversible chemical reaction is one in which the products, as soon as they are formed, react to produce the original reactants.