Question

 

The mass of one litre sample of ozonised oxygen at N.T.P was found to be 1.5 g. when 100mL of this mixture at N.T.P were treated with turpentine oil, the volume was reduced to 90mL

Calculated the molecular mass of ozone. 

Solution

Correct option is

48

 

As ozone is absorbed by turpentine oil, therefore volume of ozone in 100mL of the mixture

                        = 100 – 90 = 10mL

As 1 L of the mixture weigh = 1.5 g, therefore, average molar mass of the mixture

                                    

Ratio of ozone: oxygen in the mixture = 10 : 90

If m is the molecular mass of ozone, then

Average mol. mass of mixture 

                                               = 33.6 (calculated above)

or + 228 = 336

or           m = 48 

SIMILAR QUESTIONS

Q1

Insulin contains 3.4% sulphur. Calculate the minimum molecular mass of insulin.

Q2

 atoms of iron weigh as much as 1cc of H2 at S.T.P. What is the atomic mass of iron?

Q3

4 g carbon were heated with 8 g of sulphur. How much carbon disulphide (CS2) will be formed when the reaction is completed? What will be its percentage purity?  

Q4

How many years would it take to spend Avogadro’s number of rupees at the rate of 10 lakh rupees per second?

Q5

Gastric juice contains about 3.0 g of HCl per litre. If a person produces about 2.5litre of gastric juice per day, how many antacid tablets each  containing 400 mg of Al(OH)­3 are needed to neutralize all the HCl produced in one day. 

Q6

What volume at N.T.P of ammonia gas will be required to be passed into 30mL of N H2SO4 solution to bring down the acid normality to 0.2 N?

Q7

The vapour density of a mixture of NO2 and N2O4 is 38.3 at 26.7oC. Calculate the number of moles of NO2 in 100 g of the mixture.

Q8

7.4 gram of a metal hydroxide on heating gives 5.6 g of metal oxide. Calculate the equivalent weight of the metal.

Q9

How many molecules are there in 10 litres of gas at a pressure of 75 cm at 27 degree Celsius? 

Q10

Potassium bromide, KBr contains 32.9% by mass of potassium. If 6.40 g of bromine reacts with 3.60 g of potassium, calculate the number of moles of potassium which combine with bromine to from KBr.