Group 1: the alkali metalsIB MYP Chemistry: Mind map

Exam questions on Group 1: the alkali metals

1. A school technician in Singapore is preparing a demonstration for a Year 9 class. A small piece of sodium is taken from a bottle of oil, cut with a knife, dried and dropped into a large trough of water containing a few drops of universal indicator. The class will watch from behind a safety screen.
   Write the word equation for the reaction of sodium with water.2 marks
2. A teacher drops equal-sized small pieces of lithium, sodium and potassium into three separate troughs of water. Lithium floats and fizzes steadily until it disappears. Sodium floats, melts into a silvery ball and fizzes rapidly, darting across the surface. Potassium floats, melts, darts about very quickly and burns with a lilac flame.
   Explain, in terms of electrons, why potassium is more reactive than sodium.2 marks
3. A student wants to compare the reactivity of lithium, sodium and potassium. She plans to add a small piece of each metal, one at a time, to a large beaker of water at room temperature and to time how long each piece takes to stop fizzing. Her teacher will cut and dry each piece for her.
   State a testable hypothesis for her investigation, with a scientific reason, and identify the independent variable.3 marks