Unit 1 States & Separation

• (NOTE: ANS in no spaces) The best method for separating the dyes in black ink is chromatography
• (NOTE: ANS in no spaces) The best method for obtaining pure water from seawater is simpledistillation.
• The procedure for separating salt water with sand is:
• (NOTE: ANS in no spaces)

  1. The mixture of salt water with sand can be separated by first dissolving the salt in distilled water.
  2. The sand is then removed by filtering.
  3. Some of the water from the salt water solution is then removed by evaporating.
  4. A pure sample of hydrated salt is then obtained by crystallisation.

  Note: The best method to just obtain water from a mixture containing salt and water is simpledistillation.
• In a chromatogram, the solvent is the mobile phase and the substance being separated is the stationary phase. If a substance just remains on the baseline, it is because it is insoluble in the solvent.
• Fill in the blanks for the possible state each substance is in the chemical equation:

  NH3 (g) + HCl (g)→ NH4Cl (s)

  
• Letters A and B represent atoms of the same element because they both have the same number of protons. They are also neutral atoms because the number of protons and electrons are the same.