1. write the reaction rate expressions for the following reactions in terms of the disappearance of the reactants and the appearance of products: (6 points) a. h2(g) + i2(g) → 2hi(g) b. 5br–(aq) + bro3–(aq) + 6h+(aq) → 3br2(aq) + 3h2o(l)

The expressions are written below.

Explanation:

The rate of reaction is defined as the change in the concentration of any one of the reactants or products per unit time. For the general reaction:

Expression for the rate of reaction is given as:

Or,

Thus,

The given chemical reaction follows:

Rate of the reaction for disappearance of is given as:

Rate of the reaction for appearance of is given as:

The given chemical reaction follows:

Rate of the reaction for disappearance of is given as:

Rate of the reaction for appearance of is given as:

Hence, the expressions are given above.

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.