Chemistry Spring Term AP2 - Acids and Alkalis Flashcards
What is a universal indicator?
an indicator that can be used to measure the approximate pH of a solution
Name 4 properties of alkalis
- is bitter in taste and feels soapy.
- turns litmus paper blue.
- has a pH value of more than 7.
- always contains hydroxide (OH) which is very reactive
Name 4 properties of acids
- are sour in taste and can be corrosive
- turns litmus paper red
- has a pH of under 7
- always contains hydrogen (H) which is very reactive
What are the products of neutralisation?
salt + water
Which 7 elements are diatomic molecules?
Hydrogen
Nitrogen
Fluorine
Oxygen
Iodine
Chlorine
Bromine
Have No Fear Of Ice Cold Beer
What is the difference between universal indicator and litmus paper?
Universal Indicator paper displays a variety of colors over a wide pH range, unlike litmus paper which only shows 2 colours
What is the difference between a base and an alkali?
A base is a something that react with an acid to form water and a salt. An alkali is any base that is soluble in water.
All alkalis are bases, but all bases are not alkalis.
What is a metal oxide?
the metal bonded with oxygen
How do you name the salt formed in neutralisation?
The first part of the salt comes from the first word in the name of the base and the name of the acid makes the second word
salt made from hydrochloric acids end in chloride, for sulphuric acids sulphates and for nitric acids, nitrates
Give one example of a base
(that is not an alkali)
copper hydroxide
Give an example of an alkali
sodium hydroxide
Do bases have a pH
Yes, they do
What salt does calcium hydroxide + hydrochloric acid produce?
calcium chloride
What salt does magnesium oxide + nitric acid produce?
magnesium nitrate
What salt would sodium hydroxide + nitric acid produce?
sodium nitrate
What salt does magnesium hydroxide + hydrochloric acid produce?
magnesium chloride
What salt does magnesium hydroxide + nitric acid produce?
magnesium nitrate
What salt does aluminium hydroxide + nitric acid produce?
aluminium nitrate
What salt did potassium hydroxide + sulphuric acid produce?
potassium sulphate
sulphuric acid formula
H₂SO₄
(valency of 2)
ammonium formula and valency
NH₄
valency of 1
nitrate formula and valency
NO₃
valency of 1
hydroxide
OH
valency of 1
sulphate formula and valency
SO₄
valency of 2
carbonate
CO₃
valency of 2
calcium hydroxide formula
Ca(OH)₂
nitric acid formula
HNO₃
hydrochloric acid formula
HCl
(valency of 1)
What does the pH scale tell you?
- Whether a substance is an acid or alkali and the subtstance’s strength
- The power of hydrogen ions in a solution
Give an example of a household acid and household alkali
- vinegar (acid)
- washing powder (alkali)
Give an example of a useful acid-alkali reaction
- taking indigestion tablets to neutralise excess hydrochloric acid made by the stomach
- neutralising excess acids in soil to protect plants
What pollutant gases cause acid rain?
sulfur dioxide and nitrogen oxides
acid + base –> ?
acid + base –> salt + water
acid + metal oxide–>
acid+ metal oxide–> salt + water
acid + carbonate–>
acid + carbonate–> salt + water + carbon dioxide
acid + hydroxide–>
acid + hydroxide–> salt + water
sulfuric acid formula
HSO4
Name one example of a natural indicator.
Red cabbage
What is the difference between the strength of a solution and the concentration?
The strength is determined by the pH, whilst the concentration is determined by the number of particles of the solute that are present in the solution.
State the difference between a concentrated and dilute solution.
A dilute solution has a relatively small amount of the solute, whilst a concentrated solution has a relatively large amount of the particles present.
What is an oxide?
A substance made up of a metal or non-metal element joined to oxygen
what is a salt?
A salt is a compound in which the hydrogen atoms of an acid are replaced by atoms of a metal element
What is a concentrated solution?
a solution that has a large amount of solute particles per unit of volume
What is a dilute solution?
a solution that has a small number of solute particles per unit volume