1a) What are the properties of acids? b) Name some everyday products that contain acid.

2a) What is similar about the formula for hydrochloric acid and that for
sodium chloride?
b) What is different about these two formulae?

3) The illustration below shows a label on a jar of orange preserve.

Allergy advice: No nuts.
Suitable for vegetarians.
Ingredients: Sugar, oranges,
water, concentrated lemon
juice, sodium citrate, citric
acid, bitter orange oil.
Prepared with 30 g of fruit
per 100 g.

a) Which ingredient is a salt?
b) Find out why this ingredient is added to some
kinds of food.

  the   balanced   equation   for   reaction of   ca metal   with   o2 to   produce   cao   is as below

2 ca+ o2→ 2 cao2

  explanation

the reaction is   balanced     since the   number of atoms   in reactant side is   equal to   number of atoms   in   product side.   for   example   they   are 2   atom of   ca in   reactant   side   and   2   atoms of ca   in   the product side.

  the   process   is a   meet the   requirement   of   redox   reaction because :     calcium   is   oxidized   from   oxidation state 0   to 2+   while   oxygen   is reduced from   oxidation   state   0   to 2-

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.