Group 2, 7, Analysis Flashcards
What is a reducing agent?
A species which reduces another species and caused the reduced specie to gain electrons given off
What is the product formed when a group 2 element reacts with oxygen?
Metal oxide
What 2 products are formed when a group 2 element reacts with water?
Metal hydroxide + hydrogen gas
What 2 products are formed when a group 2 element reacts with dilute acids?
Salt + hydrogen gas
What is the trend in reactivity down group 2?
Increases down the group as the outer electron is further away from nucleus so nuclear charge is weaker
What is the trend in Ionisation energy down group 2?
Decreases down the group as nuclear charge is weaker
What is the trend in Ionisation energy down group 2?
Decreases down the group as nuclear charge is weaker
What 2 products are formed when a group 2 metal oxide reacts with water?
Metal 2+ ions + hydroxide ions
What is the trend in solubility down group 2?
Increases as each element become more alkali and so more OH‐ ions are released
Outline the steps in the trend experiment for group 2 elements
Add a spatula of each group 2 oxide to individual test tubes and add water
Shake until white precipitate forms
Measure PH of solution
How are group 2 compounds used in agriculture?
Calcium hydroxide is used to neutralise acidic soils as it produces water
How are group 2 elements used in medicine?
Magnesium hydroxide is used to help treat indigestion as an antacid
What colour does Iodine turn in aqueous solution?
Brown
What colour does Iodine turn in cyclohexane?
Purple
What colour is Iodine in its natural form?
Silver
What colour is chlorine?
Green
What colour is bromine?
Orange
What colour is fluorine?
Yellow
What is the trend in boiling point down group 7?
Increases due to there being more electrons so stronger London forces requiring more energy to overcome
Name one benefit and one weakness of using chlorine
Benefit- kills harmful bacteria
Weakness- can be toxic if inhaled
How do you test for halide ions?
Mix ion with aqueous silver nitrate and a coloured precipitate will form
What happens to the halogen and the halide in a displacement reaction?
The more reactive halogen will displace the halide form its compound. Halogen gains electrons so is the oxidising agent and the halide loses electrons so is thr reducing agent
Outline the carbonate test
Add nitric acid to solution, bubbles of carbon dioxide should form. Test the bubbles with lime water it should go cloudy
Outline the sulfate test
Add either barium chloride or barium nitrate, a white precipitate should form showing presence of a sulfate
