Which statement about organic compounds is true?
A compound that contains oxygen and hydrogen is organic if the compound lacks carbon.
A compound that a living organism requires for survival is considered to be organic.
An organic compound typically has at least one carbon–hydrogen or carbon–carbon bond.
A naturally‑occurring compound is organic, whereas a synthetic compound is inorganic.

An organic compound typically has at least one carbon–hydrogen or carbon–carbon bond.

Explanation:

It is true that organic compounds have one or more carbon atoms covalently bound to other atoms like hydrogen, oxygen etc

Examples of organic compounds include:

- methane (CH3)

- ethanol (C2H5OH)

In methane, carbon–hydrogen bond is present; while in ethanol both one carbon–hydrogen and carbon-carbon bond is present.

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.