Draw the alkyne you would start with to synthesize pentane. draw the molecule on the canvas by choosing buttons from the tools (for bonds and charges), atoms, and templates toolbars.

Structure of alkynes has been shown below

Explanation:

Alkynes are fully hydrogenated to alkanes by and a metal catalyst e.g. Raney Ni, Pd-C etc.

Here alkynes get stuck onto metal catalyst surface leading to complete hydrogenation of triple bond by .

Reaction occurs in SYN-addition fashion where adds onto unsaturated bond from same side.

Full reaction scheme has been shown below.  

definition

                    entropy is a measure of the randomness or the extent of disorder of a chemical process.

                      enthalpy is a measure of the heat change of a reaction occurring at a constant pressure.

measurement units:

                        entropy is measured in joule per kelvin (jk⁻¹)   whereas enthalpy is measured in joule per mole (jmol⁻¹)

requirements:

                            entropy has no requirements or limits, and its change is measured by the division between the heat change of the chemical process and the temperature.

                              in contrast, enthalpy can only be related to the heat change of the reaction under standard conditions.