Given the balanced equation representing a reaction:

CH4(g) + 2O2(g) —> CO2(g) + 2H2O(g) + energy

Which change in reaction conditions will increase the frequency of effective collisions between reactant molecules ?

a. increasing the volume of the reactants
b. increasing the concentration of the reactants
c. decreasing the pressure of the reactants
d. decreasing the temp. of the reactants

answer; ///i do believe that the correct answer is (b); ///particle composed of two or more atoms bonded together;

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.

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.