Enzymes in yeast catalyze the conversion of glucose to ethanol. This is an example of:
A. Saponification
B. Esterification
C. Oxidation
D. Fermentation
Answer: Option D
Solution (By JKExamLibrary)
Fermentation is an anaerobic biological process in which enzymes (zymase) convert glucose to ethanol and CO₂: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂. Oxidation would require oxygen. Esterification forms esters, saponification makes soap. Fermentation is used in brewing, winemaking, and baking (where CO₂ makes bread rise). The temperature is kept around 30-35°C.
Explanation:
Lead-acid battery uses dilute sulfuric acid (H₂SO₄) as the electrolyte with lead dioxide (PbO₂) as positive plate and spongy lead (Pb) as negative plate. Discharge reaction: Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O. It is a secondary (rechargeable) battery used in automobiles. The specific gravity of electrolyte indicates the state of charge. KOH is used in Ni-Cd and alkaline batteries.
Explanation:
CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂↑. Carbon dioxide turns limewater milky. This is a test for carbonates and bicarbonates. The reaction is used in laboratory preparation of CO₂.
Explanation:
LPG (propane/butane) is odorless. A small amount of strong-smelling mercaptan (ethanethiol) is added to help detect gas leaks, preventing accidents. Natural gas also has odorant. Mercaptans contain sulfur, and their smell is detectable at very low concentrations. Calorific value, temperature, performance are unaffected. Safety is primary.
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