Chemical Cells, Acids & Alkalis Flashcards
How can a simple chemical cell be made?
By connecting two different metals together with an electrolyte between them.
What is meant by an “Electrolyte”?
A solution that can conduct an electrical current.
What causes a current to flow in a cell?
A chemical reaction takes place inside the cell causing electrons to flow from the negative terminal of the cell around the circuit and back to the positive terminal.
What is a “Battery”?
Two (or more) cells connected together.
What is meant by “Voltage”?
The amount of energy supplied
to the charges passing through the cell.
Why does a cell “run out”?
The chemicals in the reaction that produces the flow of charges are used up.
What is the charge carrier in an electrical circuit?
Electrons
What is meant by the “Reactivity” of an metal?
A measure of how quickly the metal reacts.
What is the “Reactivity series”?
Common metals listed in order of reactivity, most reactive at the top, least reactive at the bottom.
Will two copper rods in an electrolyte form a chemical cell and generate a voltage?
No - It must be two different metals.
Which will produce the most voltage :
A. Two metals next to each on the reactivity series.
or
B. Two metals, one at top and one at the bottom of the reactivity series.
B - The larger the difference in reactivity, the larger the voltage generated.
What is meant by an “Acid”?
A chemical with a pH of less than 7
What is meant by an “Alkali”?
A chemical with a pH of more than 7
What is meant by “Neutral”?
A chemcial with a pH of 7
What is meant by “Irritant”?
A chemcial which will make the skin itchy, swollen and red.
What is meant by “Corrosive”?
A chemical which will dissolve metal or destroy skin and other tissues.
What is an “Indicator”?
A chemical which changes colour on contact with either an acid or an alkali.
What is meant by the “pH scale”?
A scale from 1-14 showing whether a substance is an acid, alkali or neutral.
The lower the number below 7, the stronger the acid.
The higher the number above 7, the stronger the alkali.
When an acid is added to water, what is the name given to the solution?
An acidic solution.
When an alkali is added to water, what is the name given to the solution?
An alkaline solution.
What is the name of the reaction that occurs when an acid and alkali are mixed together.
A neutralisation reaction.
What is the word equation for a Neutralisation reaction.
acid + alkali → salt + water
