Test Tube Tests Flashcards
What is observed when sodium carbonate is added to an acid?
Effervescence (CO2 gas is released)
What is observed when acidified potassium dichromate is added to a primary/secondary alcohol or an aldehyde?
The dichromate is reduced changing from orange to green
What happens to an aldehyde when it is tested using Tollen’s reagent?
- also state observation
the aldehyde is oxidised to a carboxylic acid
- silver mirror forms
What reagent is used to test for ammounium ions?
- what is observed
- state gas released when the reagent reacts with ammonium ions
Heat with NaOH
- gas released turns red litmus paper blue
- ammonia gas (NH3)
What is the test for sulfate ions (SO4 2-)
acidified barium chloride
How do you test for magnesium ions?
Add NaOH. This forms Mg(OH)2 which is a white precipitate
What would you expect to see when barium carbonate (BaCO3) is added to sulfuric acid (H2SO4
Effervescence and a white precipitate
Which is the least soluble Group 2 hydroxide?
Which is the most soluble Group 2 hydroxide?
least : Mg(OH)2
Most : Ba(OH)2
Which is the least soluble Group 2 sulfate?
Which is the most soluble Group 2 sulfate?
least : BaSO4
Most : MgSO4
Give a medical use of barium sulfate
Stomach X-rays
Give a use for magnesium hydroxide
To neutralise stomach acid
What is observed when Ba reacts with water?
A colourless solution and effervesence (fizzing)
State the observation for this reaction
NaCl(s) + H2SO4(aq) –> NaHSO4(s) + HCl(g)
Steamy Fumes
What is the observed when bromide ions reactant with sulfuric acid in a redox reaction
Acidic gas (SO2)
Brown fumes (Br2)
State the three different sulfur products that can be formed when iodide ions react with sulfuric acid in a redox reaction.
Sulfur dioxide (SO2)
Sulfur (S)
Hydrogen sulfide (H2S)
What is observed when this reaction occurs?
Ag+(aq) + F-(aq) –> AgF(aq)
Colourless solution
What is observed when this reaction occurs?
Ag+(aq) + Cl-(aq) –> AgCl(aq)
White precipitate
What is the test for halide ions?
Acidified silver nitrate (AgNO3)
Why must a halide solution be acidified before testing with silver nitrate?
To remove carbonate ions
For chlorine, iodine and bromine state what happens when it reacts with AgNO3 and then when dilute and concentrated ammonia is added
State the observation for the reaction
Cl2(aq) + 2NaI(aq) –> I2(aq) + 2NaCl(aq)
Brown solution (I2 is formed)
Why does an alkene decolourise bromine water?
It reacts by electrophilic addition
