topic 9 separate chemistry

Question 1

explain why the test for any ion must be unique

Answer 1

?

Question 2

Describe how to carry out a flame test

Answer 2

clean a wire loop in dilute hydrochloric acid, dip it into the sample solution or solid, hold the loop at the edge of a bunsen burner flame and observe the colour of the flame and use this to determine which metal ion is present

Question 3

what is the chemical test for ammonia

Answer 3

damp red litmus paper turn blue

Question 4

flame test for lithium ion Li

Answer 4

red

Question 5

flame test for sodium ion Na

Answer 5

yellow

Question 6

flame test for potassium K

Answer 6

lilac

Question 7

flame test for calcium ion Ca

Answer 7

orange red

Question 8

flame test for copper ion Cu

Answer 8

blue green

Question 9

test for ion with aluminium Al using sodium hydroxide solution

Answer 9

white precipitate , aluminium hydroxide precipitate dissolves when excess sodium hydroxide is added

Question 10

test for ion with calcium Ca using sodium hydroxide solution

Answer 10

white, no chasnge when excess sodium hydroxide is added

Question 11

test for ion with copper Cu when added to sodium hydroxide solution

Answer 11

blue precipitate

Question 12

test for ion with Iron II (fe2) when added to sodium hydroxide solution

Answer 12

green precipitate

Question 13

test for ion with Iron III (fe3) when added to sodium hydroxide solution

Answer 13

Brown precipitate

Question 14

How to test for carbonate ions

Answer 14

carbonates react with dilute acids to produce carbon dioxide and water, collect the gas given off and bubble it through lime water. The presence of a white precipitate confirms that carbonate ions were originally present in step 1

Question 15

How to test for halide ions

Answer 15

You can test to see if a solution contains chloride ions, bromide ions or iodide ions using silver nitrate solution
1-a few drops of dilute nitric acid are added to the solution
2- a few drops of silver nitrate solution are then added
3- the colour of any precipitate formed is recorded.

Question 16

if the halide ion chloride is present what precipitate will form

Answer 16

silver chloride - WHITE

Question 17

if halide ion bromide is present what precipitate will form

Answer 17

silver bromide- CREAM

Question 18

if halide ion iodide is present what precipitate will form

Answer 18

silver iodide- YELLOW

Question 19

how to test for sulfate ions

Answer 19

1- a few drops of dilute hydrochloric acid are added to solution
2- a few drops of barium chloride solution are then added
The presence of white precipitate of barium sulfate shows the presence of sulfate ions in the solution

Question 20

instrumental methods of analysis are available and they…

Answer 20

improve sensitivity, accuracy and speed of test

Question 21

evaluate data from a flame photometer

Answer 21

determine the concentration of ions in dilute solution using a calibration curve and to identify metal ions by comparing the data with reference data