Can someone just answer these two questions

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

How can a give a full method for the experiment of separating sand from water by filtration? 1-materials 2-steps 3-conclusion also for water and salt separated by the evaporation or distillation process

If 22.5 of nitrogen at 748 mm hg are compressed to 725 mm hg at constant temperature. what is the new volume?