Assertion : One mole of NaCl contains 6.023 $\times$ 10²³ molecules of sodium chloride.

Reason : 58.5 g of NaCl also contains 6.023 x 10²³ molecules of NaCl.

• If both assertion and reason are true and reason is the correct explanation of assertion.

• If both assertion and reason are true but reason is not the correct explanation of assertion.

• If assertion is true but reason is false

• If both assertion and reason are false.

A solution contains 25% H₂O , 25% C₂H₅OH and 50% CH₃COOH by mass .The mole fraction of H₂O would be :

• 0.25

• 2.5

• 0.502

• 5.03

An organic substance containing carbon , hydrogen and oxygen gave the following percentage composition .

C = 40.687 % , H = 5.085% and O = 54.228 % 

What is the empirical formula of the compound ?

• CH₃O

• C₂H₂O

• CH₄O

• C₂H₃O₂

How many grams of CO₂ will be produced by the complete combustion of 2 moles of ethanol ?

• 132 g

• 44 g

• 176 g

• 88 g

Which of the following changes with change in temperature ?

• Mole fraction

• Formality

• % (w/W)

• Molality

Equal weight of CO and CH₄ are mixed together in an empty container at 300 K. The fraction of total pressure exerted by CH₄ is.

• $\frac{16}{17}$

• $\frac{7}{11}$

• $\frac{8}{9}$

• $\frac{5}{16}$

The molarity of a 0.2 N Na₂CO₅ solution will be :

• 0.05 M

• 0.2 M

• 0.4 M

• 0.1 M

K_sp of CaSO₄.5H₂O is 9 $\times$10^-6, find the volume for 1 g of CaSO₄ (M.wt. = 136).

• 2.45 litres

• 5.1 litres

• 4.52 litres

• 3.2 litres

Which ofthe following sequence contains atomic number of only representative elements?

• 55,12,48,53

• 13,33,54,80

• 3,33,53,87

• 22,33,55,66.

580.

100 cm³ of a given sample of H₂O₂ gives 1000 cm³ of O₂ at S.T.P. The given sample is

• 10% H₂O₂

• 90% H₂O₂

• 10 volume H₂O₂

• 100 volume H₂O₂