Module 3 - Group 2 Flashcards
describe the trend in reactivity of group 2 metals
-reactivity increases down the group
explain the trend in reactivity of group 2 metals
-shielding increases
-nuclear charge increases
-nuclear attraction decreases
-atomic radius increases
-so it is easier to lose electrons
name the different reactions of group 2
- group 2 metal + water
- group 2 metal + acid
- group 2 metal + oxygen
- group 2 metal carbonate + acid
observations of group 2 metal + water
-fizzing/bubbling
-metal disappears
-heat given out (exothermic)
change in pH when group 2 metal + water
-increases
equation for group 2 metal + water
metal + water -> metal hydroxide + hydrogen
observations of group 2 metal + acid
-bubbling/fizzing
-metal disappears
change in pH when group 2 metal + acid
-increases
equation for group 2 metal + acid
metal + acid -> salt + hydrogen
observations for group 2 metal + oxygen
-bright white light
-colour change
change in pH when group 2 metal + oxygen
-increases
equation for group 2 metal + oxygen
metal + oxygen -> metal oxide
observations for group 2 metal carbonate + acid
-fizzing/bubbles
-metal carbonate disappears
change in pH when group 2 metal carbonate + acid
-increases
equation for group 2 metal carbonate + acid
metal carbonate + acid -> salt + carbon dioxide + water
describe solubility of group 2 compounds
-the oxides of group 2 elements can react with water, releasing hydroxide ions and forming a metal hydroxide
-this hydroxide is alkaline
describe the trend in solubility of group 2 compounds
-increases down the group
-so number of OH- ions in solution increases
-so pH increases
describe the uses of group 2 compounds
-group 2 bases are often used as antacids for indigestion
-group 2 metal barium can react with sulphate to make barium sulphate for use in barium meals, as it is insoluble in water and forms a white precipitate
-calcium hydroxide is used to neutralise soil in agriculture
