Unit 4 Flashcards
State the range of the pH scale
0 to 14
Write the word equation for a neutralisation reaction between an acid and an alkali
Acid + alkali = salt + water
Explain why a burette is useful for identifying the Endpoint of a titration
A burette allows an acid to be added drop by drop which helps determine the Endpoint more accurately
Why should titration results be repeat
To achieve several consistent readings. The mean of these readings is then more accurate
Describe the difference in pH between a strong acid and a weak acid
The stronger acid would have a lower pH because it is stronger, so the concentration of H+ ions would be greater
What does increasing the concentration of a solution by a factor of 10 do to the pH
Decrease it by 1
What is the word equation for the reaction of a metal and water
Metal + water = metal hydroxide + hydrogen
Why does sodium react more vigorously with water than calcium
It forms positive ions more easily/ it is higher in the reactivity series
Why are most metals found in the earth as compounds
Many elements react with oxygen to form compounds
What is an electrolyte
A solution that can conduct electricity
Why is electrolysis not the usual method of extracting iron
Iron can be extracted by reduction with carbon which is less expensive than electrolysis
