K2S (aq) + CoCl2( aq) -----> 2KCl (aq) + CoS (s)
potassium + cobalt potassium chloride + carbonyl sulfide
sulfide chloride
carbonyl sulfide :- it is chemical compound with linear formula (OCS ) normally written as (CoS) .it does not show its structure . its is colorless flammable gas with an unpleasant odour.
Potassium chloride :- It is metal halide salt composed of potassium and chlorine. it is odorless and has white or colorless crystal appearance <span />
Answer:
2.28
Explanation:
HCl(l) ===> H+ + cl-
HCl is a very strong acid. Almost all of it will decompose to the right. That means the concentration of H+ is 0.00530
pH = - log [H+]
pH = - log[0.00530]
pH = - - 2.2757
pH = 2.2757
Rounded this 2.28
Answer: The precipitate formed is 
Explanation:
A double displacement reaction is one in which exchange of ions take place. The salts which are soluble in water are designated by symbol (aq) and those which are insoluble in water and remain in solid or precipitated form are represented by (s) after their chemical formulas.
A double displacement reaction in which one of the product is formed as a solid is called as precipitation reaction.
The balanced chemical equation is:

Answer: -
0.1 ml of bleach should be added to each liter of test solution.
Explanation:-
Let the volume of bleach to be added is B ml.
Density of stock solution = 1.0 g/ml
Mass of stock solution = Volume of stock x density of stock
= B ml x 1.0 g/ml
= B g
Amount of NaOCl in this stock solution = 5% of B g
=
x B g
= 0.05 B g
Now each test solution must be added 5 mg/l NaOCl.
Thus each liter of test solution must have 5 mg.
Thus 0.05 B g = 5 mg
= 0.005 g
B = 
= 0.1
Thus 0.1 ml of bleach should be added to each liter of test solution.