C5 Chemical Changes Flashcards
(103 cards)
1
Q
Is carbon more or less reactive than iron?
A
More reactive
2
Q
A substance does not corrode in air or water. What word could describe this substance?
A
Non-corrosive
3
Q
Magnesium sulphate can be made by reacting magnesium metal with an acid. A gas is also produced. Name this gas.
A
Hydrogen Gas
4
Q
What is an ion?
A
The charged particle formed when an atom gains or loses electrons
5
Q
What is a displacement reaction?
A
When a more reactive substance takes the place of a less reactive substance
6
Q
What is an alkali?
A
A soluble base
7
Q
What is reduction?
A
The loss of oxygen OR the gain of electrons
8
Q
What are bases?
A
Ionic compounds that can neutralise acids
9
Q
What is oxidation?
A
The gaining of oxygen OR the loss of electrons (OIL)
10
Q
Metal + Oxygen =
A
Metal oxide
11
Q
Metal + Water =
A
Metal hydroxide + hydrogen
12
Q
Metal + acid =
A
Metal salt + hydrogen
13
Q
Acid + base =
A
Salt + water
14
Q
Acid + Alkali =
A
Salt + water
15
Q
Acid + carbonate =
A
Salt + water + carbon dioxide
16
Q
What is the charge of a group 1 metal?
A
+1
17
Q
What is the charge of Ammonium?
A
+1
18
Q
What is the charge of a group 2 metal?
A
+2
19
Q
What are the charges of Group 7 metals?
A
-1
20
Q
What is the charge of Aluminium?
A
+3
21
Q
What are the charges of Group 7 metals?
A
-1
22
Q
What is the charge of a Nitrate?
A
-1
23
Q
What is the charge of a Hydroxide?
A
-1
24
Q
What is the charge of a Sulphate?
A
-2
25
What is the charge of a Carbonate?
-2
26
What is the charge of an oxide?
-2
27
What salt does hydrochloric acid form?
Chlorides
28
What salts do Sulphuric acids form?
Sulphates
29
What salts do Nitric acids form?
Nitrates
30
Order the following fastest to slowest reactions - iron rusting, spaghetti cooking, rifles firing, rocks weathering, milk going sour, fireworks burning
Rifles firing, fireworks burning, spaghetti cooking, milk going sour, iron rusting, rocks weathering
31
What happens in a chemical reaction?
Substances react to make something new, indicated by chemical and physical changes
32
What are the signs of a chemical reaction?
Colour change, pop sound, fizzing
33
How do you calculate rate of reaction?
Rate = Quantity of product / Time
34
What is a catalyst?
A substance that increases the rate of reaction without itself undergoing any permanent chemical change
35
Why does reaction slow down on an annotated rate graph?
Less collisions, no more reactants - product formed
36
Give the 4 ways to speed up a reaction:
1. Increasing temperature
2. Increasing the concentration
3. Increasing the pressure
4. Increasing the SA:V ratio
37
What is collision theory?
In order for a reaction to take place reactant particles must collide with sufficient energy
38
The more collisions per second the ---------- the rate of reaction
Faster
39
What is an ion?
The charged particle formed by the loss or gain of electrons
40
What is a displacement reaction?
When a more reactive substance takes the place of a less reactive substance
41
What is oxidation (REDOX)?
The gaining of oxygen or the loss of electrons
42
What is reduction (REDOX)?
The loss of oxygen or the gain of electrons
43
What is a base?
Ionic compounds that can neutralise acids
44
What is an alkali?
A soluble base
45
Metal + oxygen --->
Metal oxide
46
Metal + water --->
Metal hydroxide + hydrogen
47
Metal + acid --->
Metal salt + hydrogen
48
Acid + base --->
Salt + water
49
Acid + alkali --->
Salt + water
50
Acid + carbonate --->
Salt + water + carbon dioxide
51
What is the charge of group 1 metals?
+1
52
What is the charge of a nitrate ion?
-1
53
What is the charge of a hydroxide ion?
-1
54
What is the charge of a sulphate ion?
-2
55
What is the charge of an oxide ion?
-2
56
What is the charge of a carbonate ion?
-2
57
What is the charge of group 7 elements?
-1
58
What do more reactive metals occur as?
Ores
59
What does Hydrochloric acid (HCl) form?
Chlorides (Cl-)
60
What does Sulphuric acid (H2SO4-2) form?
Sulphates (SO4-2)
61
What does Nitric acid (NO3-) form?
Nitrates (NO3-)
62
What is the state symbol for a solid?
s
63
What is the state symbol for a liquid?
l
64
What is the state symbol for a gas?
g
65
What is the state symbol for aqueous?
aq
66
What are the 3 steps to follow when forming ionic and half equations?
1. Write a balanced symbol equation - with states
2. Separate the ions into single elements and add the charges
3. Delete the species that appear exactly the same on both sides (should now be 2 charged elements per side)
FOR HALF EQUATIONS ONLY: Balance charges of the 2 elements on either side by expressing the number of electrons which would need to be added to form a neutrally charged atom
67
What does reactivity depend on?
Tendency to form metal ions
68
What does OILRIG stand for?
Oxidation is Loss of electrons
Reduction is Gain of electrons
69
Metal + Oxygen --->
Metal Oxide
70
Metal + Water --->
Metal Hydroxide + Hydrogen
71
Metal + Acid --->
Metal Salt + Hydrogen
72
What is the equation for neutralisation?
H+ + OH- --> H20
73
What is the neutral pH?
7
74
Are hydrogen ions positive or negative?
Always positive
75
Are hydroxide ions positive or negative?
Always negative
76
How do strong acids ionise?
Strong acid completely ionises in water - all molecules split up into ions and stay split up so it breaks down fully into its ions. Remember hydrogen ions are always positive
77
How do weak acids ionise?
Weak acids only partially ionise in water. Only 2 of the acid molecules usually split apart. The number of H+ ions is much less, so the pH of the acid will be higher
78
What is the function of cyolite?
Reduces the melting point
79
Which electrode is positive?
Anode
80
Which electrode is negative?
Cathode
81
Which electrode attracts positive metal ions?
Cathode (Cations)
82
Which electrode attracts negative metal ions?
Anode (Anions)
83
What are the top 3 most reactive metals?
Potassium, Sodium, Calcium
84
What are the only 4 elements less reactive than Hydrogen?
Copper, Silver, Gold, Platinum
85
What is a displacement reaction?
When a more reactive metal is reacted with a compound containing a less reactive metal it will replace that metal in the compound
86
What are the 4 signs of chemical change for displacement reactions?
Bubbles, temperature change, precipitate (solid forming), colour change
87
When are metals more reactive?
If they lose outer shell electrons more easily
88
What are examples of neutral (pH 7) substances?
Pure water
89
What are examples of basic/alkaline (pH 8-14) substances?
Bleach, soap, baking soda
90
What are examples of acidic (pH 0-6) substances?
Lemon, stomach acid, milk
91
What happens when acidic substances dissolve in water?
When acidic substances dissolve in water they dissociate - the acid breaks apart to release hydrogen (H+) ions (ionising)
92
What type of substance has an excess of H+ ions?
Acid
93
What type of substance has an excess of OH- ions?
Alkaline/base
94
What is concentration?
How much acid there is per unit of volume
95
What is strength (of an acid)?
How much an acid dissociates
96
Metal + water -->
Metal hydroxide
97
Metal + oxygen -->
Metal oxide
98
Metal + acid -->
Salt + hydrogen
99
Metal oxide + acid -->
Salt + water
100
Metal hydroxide + acid -->
Salt + water
101
Metal carbonate + acid -->
Salt + water + carbon dioxide
102
Ammonia + acid -->
Ammonium Salt
103
What is a base?
A substance which neutralises an acid
