Acommon concentration unit used commercially is percent weight per volume (%w/v) which is the number of gram of solute in 100 ml of solution. a bottle of hydrogen peroxide contains 2.5 %w/v hydrogen peroxide (h2o2). what is the molar concentration of hydrogen peroxide in the solution?

Explanation:

1) Data:

a) % w/v = 2.5%

b) compound: H₂O₂ (from a table molar mass = 34.0147 g/mol)

c) M = ?

2) Formulae:

a) % w/v = (mass of soulte / volume of solution) × 100

b) numer of moles, n = mass in grams / molar mass

c) M = number of moles of solute / liters of solution

3) Solution:

a) Take a base of 100 ml of solution (0.100 liter):

b) Calculate the number of moles of solute, n:

c) Calculate the molarity, M:

Round to two significant figures: 0.74 M ← answer

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.