Unit 4 Flashcards Preview

Z-Chemistry- Wrong Answers > Unit 4 > Flashcards

Flashcards in Unit 4 Deck (11)
Loading flashcards...
1

State the range of the pH scale

0 to 14

2

Write the word equation for a neutralisation reaction between an acid and an alkali

Acid + alkali = salt + water

3

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

4

Why should titration results be repeat

To achieve several consistent readings. The mean of these readings is then more accurate

5

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

6

What does increasing the concentration of a solution by a factor of 10 do to the pH

Decrease it by 1

7

What is the word equation for the reaction of a metal and water

Metal + water = metal hydroxide + hydrogen

8

Why does sodium react more vigorously with water than calcium

It forms positive ions more easily/ it is higher in the reactivity series

9

Why are most metals found in the earth as compounds

Many elements react with oxygen to form compounds

10

What is an electrolyte

A solution that can conduct electricity

11

Why is electrolysis not the usual method of extracting iron

Iron can be extracted by reduction with carbon which is less expensive than electrolysis