A chemist prepares a solution by adding 293 mgmg of K2Cr2O7K2Cr2O7 (MWMW = 294.19 g/molg/mol ) to a volumetric flask, and then adding water until the total volume of the contents of the flask reaches the calibration line that indicates 250 mLmL . Determine the molarity of the prepared solution.

The molarity of solution will be 0.00325 M

Explanation:

Molarity : It is defined as the number of moles of solute present per liter of the solution.

Formula used :

where,

n= moles of solute =

given mass = 239 mg = 0.239 g  (1g=1000mg)

moles of

= volume of solution in ml = 250 ml

Now put all the given values in the formula of molarity, we get

Therefore, the molarity of solution will be 0.00325 M

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.

answer: -

reaction:

na + cl ⇌ nacl

balanced chemical equation:

na + 2cl ⇌ nacl2

sodium + clorine goes to form sodium chloride (table salt).

the product is nacl2.

and the reactants are na and cl.

(note: if you don’t know what ⇌ means, read below: -

⇌(double head arrow) means reversible reaction).