A 4.00-gram sample of sodium chloride was added to a beaker containing 40.0 mL 0.033 M lead(II)
nitrate solution. Lead(II) chloride was precipitated according to the following reaction.
2NaCl(s) + Pb(NO3)2 (aq)  PbCl2(s) + 2NaNO3(aq)
Calculate the mass of lead(II) chloride that can be recovered. Pb = 207; Na = 23; Cl = 35.5; N = 14;
O = 16.

your answer would be a. 12.5 kg

it means there are 3 atoms of oxygen

hurricanes form when warm, moist air from the ocean surface quickly rises into the atmosphere and forms storm clouds and rain. when the clouds are formed, heat is released which warms the cool air in the upper regions of the atmosphere so that the cycle can continue. which two phases of the water cycle are repeated in this process?

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.