Acids + Electrolysis Flashcards
What ions make aqueous solutions acidic?
Hydrogen ions (H+)
Which ions make aqueous solutions alkaline?
Hydroxide ions (OH-)
What is the pH scale?
The pH scale ranges from pH 0 to pH 14 and measured the acidity and alkalinity of a solution
What can be used to measure pH
Universal indicator
ph Probe
What colour is phenolphthalein in acid and alkali and neutral?
Acid - colourless
Alkali - Pink
Neutral - colourless
What colour is methyl orange in acid and an alkali and neutral?
Acid - red
Alkali - yellow
Neutral - yellow
What colour is blue litmus paper is an acid and alkali?
Acid - turns red
Alkali - stays blue
What colour is red litmus paper in acid and alkali
Acid - stays red
Alkali - turns blue
Suggest a problem with using universal indicator to test the pH of a solution
The colour of the solution is matched to a pH colour chart. This is quite subjective as people may disagree with which colour the solution matches.
It doesn’t provide an exact pH value.
If pH decreased by one unit, what happens to the concentration hydrogen ions concentration
H+ conc Increases by a factor of 10
What is a neutralisation reaction? During an acid-alkali neutralisation reaction, what happens?
A neutralisation reaction is a reaction between an acid and a base.
In an acid-alkali neutralisation, H+ ions from the acid react with OH- ions from the alkali to form water.
What is ionic equation for a neutralisation reaction?
What do the terms concentrated and dilute mean when talking about acid? Is this the same as strong/weak acids?
Concentrated acids have more moles of acid per unit volume of water than dilute acids
Strength refers to whether the acid has completely dissociates in water or not.
An acid that only partially dissociates into H+ ions in water …
Is a weak acid
A base is..
Any substances that reacts with an acid to form salt and water only
Alkalis are..
Soluble bases.
Metal + acid —>
Salt + hydrogen
Metal oxide + acid
Salt + water