Question

7. Write a formula for each of the following:

Answer 1

Answer:

$\huge \boxed{{C_{22} H_{46} \ \ \ \ C_{17} H_{34} \ \ \ \ C_{13} H_{24}}}$

Explanation:

$alkanes \ \Rightarrow \ C_n H_{2n+2}$

$C_{22} H_{2(22)+2}$

$C_{22} H_{44+2}$

$C_{22} H_{46}$

$alkenes \ \Rightarrow \ C_n H_{2n}$

$C_{17} H_{2(17)}$

$C_{17} H_{34}$

$alkynes \ \Rightarrow \ C_n H_{2n-2}$

$C_{13} H_{2(13)-2}$

$C_{13} H_{26-2}$

$C_{13} H_{24}$

Answer 2

Answer : The formula for each of the following is:

(a) $C_{22}H_{46}$

(b) $C_{17}H_{34}$

(c) $C_{13}H_{24}$

Explanation :

• Alkanes are hydrocarbon in which the carbon atoms are connected with single covalent bonds.

The general formula of alkanes is $C_n H_{2n+2}$ where n is the number of the carbon atoms present in a molecule of alkane.

• Alkenes are hydrocarbon in which the carbon atoms are connected with double covalent bonds.

The general formula of alkenes is $C_n H_{2n}$ where n is the number of the carbon atoms present in a molecule of alkene.

• Alkynes are hydrocarbon in which the carbon atoms are connected with triple covalent bonds.

The general formula of alkynes is $C_n H_{2n-2}$ where n is the number of the carbon atoms present in a molecule of alkyne.

(a) An alkane with 22 carbon atoms

Putting n = 22 in the general formula of alkane, we get the formula of alkane as, $C_{22}H_{2(22)+2}$ or $C_{22}H_{46}$

(b) An alkene with 17 carbon atoms

Putting n = 17 in the general formula of alkene, we get the formula of alkene as, $C_{17}H_{2(17)}$ or $C_{17}H_{34}$

(c) An alkyne with 13 carbon atoms

Putting n = 13 in the general formula of alkyne, we get the formula of alkyne as, $C_{13}H_{2(13)-2}$ or $C_{13}H_{24}$