Explanation

The first organic compound prepared in the laboratory was Urea. 

German chemist Friedrich Wöhler synthesized urea from ammonium cyanate in 1828,

Marking a significant milestone in organic chemistry. 

Explanation

Octyl acetate is a natural ester known for its fruity, orange-like aroma.

It is commonly used in flavorings and perfumes to mimic orange scent.

Explanation

The mass of one mole of electrons is 0.55g.      

- Mass of one electron ≈ 9.109 × 10⁻³¹ kg

- 1 mole of electrons = 6.022 × 10²³ electrons

- So, mass of 1 mole of electrons ≈  

  9.109 × 10⁻³¹ kg × 6.022 × 10²³ ≈ 5.48 × 10⁻⁴ kg ≈ 0.548 g

So the correct value is about 0.55 g

Explanation

The elements in group VIIA of the periodic table are called halogens.

This group consists of the following elements:

• Fluorine (F)
• Chlorine (Cl)
• Bromine (Br)
• Iodine (I)
• Astatine (At)
• Tennessine (Ts)

Explanation

The most stable hydrocarbon among the given options is trans-2-butene. 

Stability in alkenes:

• The stability of alkenes is primarily determined by the degree of substitution at the double bond.
• More substituted alkenes are generally more stable. 

Trans vs. Cis Isomers:

• In the case of 2-butene, the trans isomer is more stable than the cis isomer.
• This is because in the trans configuration, the alkyl groups on either side of the double bond are oriented away from each other, minimizing steric hindrance.
• In the cis configuration, the alkyl groups are on the same side, leading to steric repulsion and less stability. 

Explanation

Ethylene glycol (HOCH2CH2OH) is a 1,2-diol, and both periodic acid (HIO4) and lead tetraacetate (Pb(OAc)4)

They are strong oxidizing agents capable of cleaving the carbon-carbon bond between the adjacent hydroxyl groups in a glycol

Resulting in the formation of carboxylic acids. In the case of ethylene glycol, this would yield oxalic acid (HOOC-COOH). 

Explanation

Affinity for oxygen refers to how readily an element or compound combines with oxygen.

Magnesium (Mg) is a highly reactive alkaline earth metal that readily loses its two electrons to form a positive Mg2+ ion.

This ion then readily combines with oxygen to form magnesium oxide (MgO), demonstrating a strong affinity for oxygen. 

Explanation

NMR spectroscopy provides detailed information about the connectivity of atoms within a molecule,

Including the types of carbon and hydrogen atoms present, their relative positions, and the presence of functional groups.

This level of detail allows for a comprehensive understanding of a molecule's structure, making it significantly more informative than the other options. 

Explanation

Graham Edgar introduced the octane number concept in the 1920s to measure the anti-knocking quality of fuels.

He established iso-octane (100) and n-heptane (0) as reference points for rating fuels.

Explanation

• CH3-OH is the molecular formula for methanol, which is an alcohol.

Key Points:

• CH3-CHO is the molecular formula for acetaldehyde, which is an aldehyde.
• CH3-CH2-O-CH3 is the molecular formula for diethyl ether, which is an ether.
• HCOOH is the molecular formula for formic acid, which is a carboxylic acid.