What volume of a 2.00 m stock solution of naoh is needed to prepare 150. ml of 0.40 m solution?

To find the volume ratios we say m1v1=m2v2

where m1 is the initial molarity, m2 the final molarity, v1 the initial volume, v2 the final volume.in this question m1=2.00M, m2=0.40M v2=150ml

Therefore the expression becomes:  2.00M×v1=0.40M×150mL

                                                           v1=(0.40M×150mL)/2.00M

                                                               =30mL

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.