C3 2021 Flashcards
Sodium ethanedioate is toxic, suggest safety precautions for filling the burette and dissolving the solid
Below eye level
Wear gloves
State the colour change seen at the end point of each titration
Colourless to pink
Give two practical steps needed before recording the initial burette reading
Remove funnel
No air bubbles
Describe how the crystalline solid is separated and purified
Filter
Dissolve in minimum volume of hot solvent
Cool and filter
Wash with cold solvent and dry
Why is KCN used instead of HCN?
HCN is weak
Equation for solid sodium bromide with conc sulfuric acid
2NaBr + 2H2SO4 -> Na2SO4 + SO2 + Br2 + 2H2O
WHat does HNO3 do in group 7
Removes any ions that may give other ppt with AgNO3
Give equation for dilute aq ammonia with silver chloride
AgCl + 2NH3 -> Ag(NH3)2+ + Cl-