For which of the following molecular formulas is the formula shown in parentheses the correct empirical formula? (a) c12h22o11 (c12h22o11), (b) c8h12o4 (c4h6o2), (c) h2o2 (h2o)?

C₁₂H₂₂O₁₁ (C₁₂H₂₂O₁₁ ).

Explanation:

The empirical formula is obtained when we divide the molecular formula with a whole number giving the simplest ratio of all the elements (in whole number).

a) C₁₂H₂₂O₁₁ :

There is no number with which we can divide the ratio further to get a simpler formula hence the molecular formula of the given compound is the empirical formula of the compound. Hence it is correct.

(C₁₂H₂₂O₁₁),

(b) C₈H₁₂O₄

The empirical formula can be obtained by dividing the formula with "4"

The empirical formula would be

(C₂H₃O)

(c) H₂O₂

The empirical formula would be (H₁O₁)

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

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.