Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Science > Chemistry Reactions > Flashcards

Chemistry Reactions Flashcards

1
Q

What is a physical change?

A

A physical change is reversible. Eg: dissolving and changes of state (melting/freezing/boiling)

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

What is a chemical reaction?

A

A chemical reaction is a change in which atoms are rearranged to make new substances.

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

Tell me 3 important facts about chemical reactions…

A

1) Atoms are rearranged to make new substances.
2) They are not reversible.
3) They also transfer energy to or from their surroundings.

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

State three pieces of evidence that suggest a chemical reaction is taking place…

A

1) Feel the substances getting hotter or colder.
2) Notice a sweet smell or foul stink.
3) See huge flames or tiny sparks.
4) Hear a loud bang or gentle fizzing.

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

State three examples of useful products made in a chemical reaction…

A

1) Medicine - such as paracetamol.
2) Fabrics such as polyester.
3) Building materials such as cement.

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

Give examples of two types of physical change…

A

1) Changes of state such as freezing, melting or boiling.
2) Dissolving - such as dissolving sugar into tea.

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

List the chemical names of three common acids.

A

1) Hydrocholric acid - stomach acid
2) Citric acid - lemon juice
3) Ethanoic acid - vinegar (diluted)

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

Name two types of alkalis.

A

Soap solution and toothpaste

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

State 2 hazards of using a corrosive substance.

A

Can burn your eyes and your skin

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

How can you control risks when handling corrosive substances?

A

1) Wear eye protection
2) Keep solution off your skin by wearing an overall
3) Wear gloves if necessary

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

The hazards of using acids and alkalis depend on…

A

1) The acid or alkali you are using.
2) Whether the solution is concentrated or dilute.

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

State what an indicator is.

A

You can use an indicator to find out whether a solution if acidic or alkaline. An indicator contains a dye. The dye turns a different colour in acidic and alkaline solutions.

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

What is the pH scale?

A

The pH scale is a measure of how acidic or alkaline a solution is.

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

What can you use to test how acidic or alkaline a substance is?

A

Universal indicator. This is a mixture of dyes. It changes colour to show how acidic or alkaline a solution is.

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

An acid has a pH of…

A

less than 7.0. The lower the pH, the more acidic to solution.

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

An alkaline has a pH of…

A

more than 7.0. The higher the number, the mores alkaline the solution.

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

Some solutions are neutral. What does this mean?

A

They are neither acidic or alkaline. The pH of a neutral solution is exactly 7.0.
Water = 7.0
Blood = 🩸 7.4

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

Name 3 strong acids

A

Hydrochloric
Sulfuric
Nitric

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

Name 2 weak acids

A

Ethanoic acid (the acid in vinegar)
Citric acid (found in a lemon)

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

What is the definition of a strong acid?

A

All the particles split up

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

What is the definition of a weak acid?

A

Only some of its particles split up

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

What is the concentration of an acid?

A

Concentration is the amount of acid dissolve in water to make 1 litre of solution. It is a measure of the number of particles in a given volume of solution.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the strength of an acid?

A

Strength is a measure of the fraction of acid particles that are split up.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is a neutralisation reaction?

A

In a neutralisation reaction, an acid reacts with a substance that cancels it out so that the pH gets closer to 7.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What is a base? Give some examples.
A base is a substance that neutralises acid. Bases in include sodium hydroxide, calcium oxide and copper oxide.
26
Some bases dissolve in water. A soluble base is called...
an alkali.
27
State one difference between a base and an alkali...
A base neutralises an acid. And a soluble base is an alkali. Alkalis are bases that dissolve in water.
28
How is neutralisation useful?
Some soils for crops are more acidic than others. Every plant has its favourite soil pH. A base can neutralise some of the soil acid so that it is more suitable to grow certain types of plants.
29
Describe two situations in which neutralisation reactions are useful?
Soil for crops. Acidic lakes.
30
How are acidic lakes created?
Gases from burning coal can make sulphur dioxide gas. This dissolves in rainwater to make acid rain. The rain falls in lakes, making them more acidic. Some water animals and plants cannot live in these lakes.
31
Describe what a salt is...
A salt is a substance that forms in the chemical reaction of an acid with a metal element, or in the reaction of an acid with a compound that contains a metal.
32
What is the salt that you add to food?
Sodium chloride.
33
Name some common salts...
Sodium chloride (table salt). Copper sulfate (farmers use to kill fungus) Cobalt nitrate (used to speed up chemical reactions)
34
The chemical reaction of an acid with a metal makes two products, which are...
a salt and hydrogen.
35
Magnesium reacts with hydrochloric acid to make...
Magnesium chloride (a salt) and hydrogen.
36
Zinc reacts with sulphuric acid to make....
Zinc sulfate (a salt) and hydrogen.
37
The chemical reaction of an acid with a base makes two products, which are...
a salt and water.
38
Sodium hydroxide reacts with hydrochloric acid to make...
Sodium chloride (a salt) and water
39
Copper oxide reacts with nitric acid to make...
Copper nitrate (a salt) and water.
40
Hydrochloric acid is a ............ maker
chloride maker
41
Nitric acid is a ............. maker
Nitrate maker
42
Removing water from salt solutions creates what?
Salt crystals
43
What is an element?
An element is a substance that contains just one type of atom. It cannot be broken down into other substances.
44
How many elements exist naturally in the world?
98
45
In laboratories around the world, scientists have discovered how many more elements?
20
46
What is the periodic table?
It lists the elements and groups together elements with similar properties.
47
What is a chemical symbol?
A one or two letter code for an element.
48
One classification of the periodic table has just two categories - what are they?
Metal and non-metals.
49
In the periodic table, where are the metals?
On the left hand of the red line.
50
In the periodic table, where are the non-metals?
On the right hand side of the red line.
51
You can tell whether an element is a metal or non-metal by looking at its....
properties.
52
Most metals have high or low melting points?
High
53
Most metals are solid/liquid/gas at room temperature?
Solid. They have high melting point. The exception is mercury which has a low melting point which means it is liquid at 20 degrees.
54
Name some metal elements which are magnetic?
Iron Nickel Cobalt Other metal elements are not magnetic.
55
Many non-metals have low boiling points. Give some examples...
Oxygen and chlorine are gases. Bromine is a liquid.
56
List some properties of a typical metal (when solid)?
Good conductor of electricity Good conductor of heat Shiny High density (heavy for its size) Malleable (you can hammer it into different shapes) and ductile (can be drawn out into a thin wire). High boiling point.
57
List some properties of a typical non-metal (when solid)
Poor conductor of electricity Poor conductor of heat Dull (not shiny) Low density (light for its size) Brittle (breaks easily) Low boiling point
58
Chemical properties describe...
chemical reactions
59
Many elements, both metal and non-metals, take part in chemical reactions with oxygen. They form new substances called....
oxides.
60
What is an oxide?
A substance that is formed when an element (metal or non-metal) takes part in a chemical reaction with oxygen.
61
Zinc reacts with oxygen to form...
Zinc oxide
62
Sulfur reacts with oxygen to form...
Sulfur dioxide
63
Describe two differences between a metal oxide and a non-metal oxide...
Most metal oxides are solid at 20 degrees and are bases. Most non-metal oxides are gases at 20 degrees and are acids.
64
In a chemical reaction, the starting substances are called...
Reactants.
65
In a chemical reaction, the substances that are made are called...
Products.
66
Some metals do not react with dilute acids. Name some...
Platinum, gold, silver or copper.
67
Name some metals which are the most reactive down to the least reactive.
Most reactive: Magnesium Zinc Iron Lead Copper, silver Platinum, gold
68
What is an oxidation reaction?
The reaction of any metal with oxygen, in which the substance combines with oxygen
69
Name two metals that react vigorously with oxygen from the air?
Zinc Iron
70
What is the reactivity of an element?
Its tendency to take part in chemical reactions.
71
Metals that react vigorously with acid, also react vigorously with.....
Oxygen.
72
Name three metals that do not react with water?
Copper (used in pipes) Stainless steel (taps, cutlery) Gold (jewellery)
73
How do Group 1 metals react with water?
Vigorously. There is a flame when potassium reacts with water. Sodium and lithium react slightly less vigorously.
74
What is the chemical reaction of Group 1 metals?
They all make soluble hydroxides and hydrogen gas.
75
Name one metal that reacts with steam but not with cold water...
Magnesium.
76
What is the reactivity series?
The reactivity series describes the patterns for metal reactions with acids, oxygen and water.
77
What is a displacement reaction?
In a displacement reaction, a more reactive element displaces a less reactive element from its compound.
78
State why copper cannot displace magnesium from magnesium sulfate solution?
Because copper is less reactive than magnesium, so it cannot displace it from its compound.
79
What is a thermite reaction?
Reaction of aluminium with iron oxide to make aluminium oxide and iron. It transfers energy to its surroundings.
80
Sulphuric acid makes ...... Hydrochloric acid makes.... Nitric acid makes.....
Sulfates Chlorides Nitrates
81
What is the word equation for burning methane?
Methane + oxygen -> water plus carbon dioxide
82
What is the symbol equation for the burning of methane?
CH4 + 2O2 -> H20 + CO2
83
What is combustion?
The scientific word for burning.
84
What products are there in combustion?
The products are always carbon dioxide and water.
85
What is incomplete combustion?
When there isn’t enough oxygen around for the complete combustion. It could make carbon monoxide rather than carbon dioxide.
86
Describe the test for Hydrogen and the result if hydrogen is present...
A test for hydrogen gas can be performed by bringing a burning candle near the source of hydrogen. Hydrogen gas burns with a squeaky POP sound.
86
Sodium hydrogencarbonate and citric acid react to form what?
Sodium citrate. Water. Carbon Dioxide.

Science (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions