testing for ions

Question 1

describe the test for aq carbonate ions

Answer 1

• add any acid
• bubbles of colourless gas
• CO2 indicates presence of carbonate

Question 2

describe the test for aq sulfate ions

Answer 2

• add BaCl2 or Ba(NO3)2
• white ppt of BaSO4 indicates presence of sulfate ions

Question 3

describe test for aq chloride ions

Answer 3

• add AgNO3
• white ppt of AgCl indicates presence of chloride ions
• AgCl dissolves in dilute NH3

Question 4

describe the test for aq bromide ions

Answer 4

• add AgNO3
• cream ppt of AgBr indicates presence of bromide ions
• AgBr does not dissolve in dilute NH3 but does dissolve in conc NH3

Question 5

describe the test for aq iodide ions

Answer 5

• add AgNO3
• yellow ppt of agI indicates presence of iodide ions
• AgI does not dissolve in either dilute or conc NH3

Question 6

describe the test for aq ammonium ions

Answer 6

• add alkali
• warm bubbles of colourless gas
• NH3 turns damp red litmus paper blue indicates presence of ammonium ions