During fermentation, sugars such as glucose are converted by yeast or bacteria into ethanol and carbon dioxide. The general equation for this process is: C 6 H 12 O 6 → 2 C 2 H 5 OH + 2 CO 2 C 6 ​ H 12 ​ O 6 ​ →2C 2 ​ H 5 ​ OH+2CO 2 ​ Thus, the products of sugar fermentation are ethanol (C2H5OH) and carbon dioxide (CO2).

Aldehydes are synthesized by the oxidation of primary alcohols. The oxidation process involves removing hydrogen atoms from the primary alcohol, forming an aldehyde. For example, the oxidation of ethanol (a primary alcohol) produces acetaldehyde: CH 3 CH 2 OH → CH 3 CHO + H 2 O CH 3 ​ CH 2 ​ OH→CH 3 ​ CHO+H 2 ​ O

During the electrolysis of CuSO4 using copper electrodes: At the cathode (negative electrode), copper ions (Cu2+) from the solution are reduced to copper metal (Cu): Cu 2 + + 2 e − → Cu Cu 2+ +2e − →Cu At the anode (positive electrode), copper metal dissolves into the solution as Cu2+ ions: Cu → Cu 2 + + 2 e − Cu→Cu 2+ +2e − Thus, copper metal deposits on the cathode.

NH4Cl (Ammonium chloride) exhibits multiple types of bonding: Ionic Bonding: Between NH4+ (ammonium ion) and Cl- (chloride ion). Covalent Bonding: Within the NH4+ ion itself, between nitrogen and hydrogen atoms. Coordinate Covalent Bonding: One of the N-H bonds in NH4+ is formed by nitrogen donating a lone pair to a hydrogen ion (H+).