Lesson No: 4 Unit Title: Solutions
 Lesson 2Lesson 3Lesson 5

Unit No: 7H

Lesson Title: Salt of the Earth — part 2

NC Ref:
Sc3 1g 2a

Objectives:
MK - Water contains dissolved chemicals, dissolved solids can be obtained by
evaporation
SK - Salt can be obtained from sea water or salt mines, conservation of mass
CK - Ghandi and the salt act.

Lesson outline:

  • Review filtering and evaporation, slip test I sudden death test.

  • Practical — Making pure salt from rock salt.

  • Follow the procedure on w/s7Hb/4

  • Students to do:

Exploring Science P92/93 and SK — W/s — 7Hb/5

  • Plenary — MK — Rock salt contains rock - insoluble, and salt - soluble.
    Salt is dissolved in water, filtered. Rock remains in filter paper. Salt is in solutio    n - evaporate.  Mass is conserved.

Homework:

  • I think all students should do WIs — 7Hb/6 and 7Hb/7

Time

Homework:  MK — 7Hb/6 and 7Hb/7

Resources: rock salt, pestle and mortar, evaporating dishes, spatulas, glass rods, filter funnels, filter paper. Exploring science 7

WS - 7Hb/4 7Hb/5 7Hb/6 and 7Hb/7

 

 

Risk Assessment: safety glasses. Be aware that evaporating too hard will make solute spit.