Question
Which of the following does not give effervescence with
sodium carbonate?Solution
Effervescence with sodium carbonate (Na₂CO₃) is due to the release of carbon dioxide (CO₂) gas when it reacts with an acid: 2CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂↑ This reaction occurs only if the compound has acidic hydrogen strong enough to liberate CO₂ from carbonate. Phenol does not give effervescence because: It is a very weak acid and does not react with carbonates or bicarbonates to release CO₂. It cannot liberate CO₂ gas due to the stability of the phenoxide ion and weak acidity.
Ethane gas has a slightly _____ taste.
Which of the following isotope of hydrogen is radioactive in nature?
Acid rain is caused due to pollution of the atmosphere by:
Magnesium has atomic number as 12. Find out its valiancy.
_________is a formula for rust.
Which polymer is formed by the copolymerization of phenol and formaldehyde?
Which endocrine gland requires iodine to synthesize a particular hormone, whose deficiency may cause goitre disease?
The motion of an object under free fall is an example of which of the following?
When cathode rays strike a target of high atomic weight, they give rise to:
Anemometer is used to measure –
