Reactions, Rates- Unit 2 Flashcards
What is formed when a substance is dissolved in water?
An aqueous solution, which can be acidic, neutral or alkaline.
What are soluble hydroxides?
Alkalis, they make an alkaline solution. Eg sodium hydroxide solution.
What are bases?
Substances that can neutralise acids. Eg metal oxides and metal hydroxides.
Name examples of acids.
Ethanoic acid, citric acid, sulphuric acid.
What is ethanoic acid found in?
Vinegar.
What is pure water described as?
Neutral, it has a pH of 7.
Name an example of an acid formed from adding water.
Hydrochloric acid. Formed when gas hydrogen chloride dissolves in water.
HCL- H+(aq) + Cl- (aq)
What ions do all acids form when added to water?
H+ ions which make solution acidic.
Are acids or alkalis used as bases in experiments?
Alkalis because they dissolve in water.
Name a alkaline solution formed when added to water.
Sodium hydroxide solution which is formed when dissolving solid sodium hydroxide,
NaOH (s)- Na+ (aq) + OH- (aq)
What ions do all alkalines form when added to water?
Hydroxide ions (OH-) which makes the solution alkaline.
What does state symbol (s) stand for?
Solid.
What are indicators?
Substances which change colour when added to acids and alkalis eg litmus paper.
What does the pH scale show?
How acidic or alkaline a solution is.
What is the Ph scale?
0-14
Most acidic- most alkaline.
What does it mean if a substance has a pH of 7?
It is neutral, neither acidic or alkaline.
What is universal indicator made from?
A number of dyes which turns a range of colours as the pH changes.
What is one way of making salts with acids?
Reacting them with metals.
How can reacting acids with metals only work?
If the metal is more reactive than hydrogen.
What will happen if a metal less reactive than hydrogen reacts with acids?
Form a salt with hydrogen gas.