900 cm³ of distilled water was added to 100cm³ of 0.5m sodium carbonate solution. calculate the concentration of the resulting solution in : -
(i) moles per litre.
(ii) grams per litre

(i) 0.05 mol/L; (ii) 5 g/L

Explanation:

We can use the dilution formula:

c1V1 = c2V2

Data:

c1 = 0.5 mol/L; V1 = 100 cm3

Added water = 900 cm3

Calculations:

(i) Moles per litre

V2 = 100 + 900 = 1000 cm^3 = 1 L

0.5 × 100 = c2 × 1000

          50 = c2 × 1000

          c2 = 0.05 mol/L

(ii) Grams per litre

c2 = 0.05 mol/L × (105.99 g/1 mol) = 5 g/L

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.

50.23 i believe is correct but don't quote me on that.