What is the molarity of 200 ml of solution in which 2.0
molesof sodium bromide is dissolved?

10 M

Explanation:

Molarity -

Molarity of a substance , is the number of moles present in a liter of solution .

M = n / V

M = molarity

V = volume of solution in liter ,

n = moles of solute ,

From the question,

V = 200mL

Since, 1L = 1000mL ,

1 mL = 0.001 L

Hence,

V = 200mL = 0.2 L

n = 2.0 mol

Hence, to calculate the molarity of the solution, the above formula can be used as -

M = n / V

M = 2.0 mol / 0.2 L = 10 M

the law of conservation of mass states that in a chemical reaction, the total mass of reactants is equal to the total mass of products. because atoms are only rearranged in a chemical reaction, there must be the same number of sodium atoms and chlorine atoms in both the reactants and products

  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-