Acid rain can damage buildings made of marble because marble is:
A. Aluminium oxide
B. Magnesium oxide
C. Calcium carbonate
D. Calcium silicate
Answer: Option C
Solution (By JKExamLibrary)
Marble is primarily calcium carbonate (CaCO₃). It reacts with acid rain (containing H₂SO₄ and HNO₃) to form soluble salts, causing erosion: CaCO₃ + H₂SO₄ → CaSO₄ + H₂O + CO₂. This is why monuments like Taj Mahal are affected. CaCO₃ is basic, so it neutralizes acid. Restoration and pollution control are needed to protect heritage.
Explanation:
Antoine Lavoisier is known as the father of modern chemistry and formulated the law of conservation of mass—mass is neither created nor destroyed in a chemical reaction. Dalton's atomic theory supported this law. Thomson discovered electron. Rutherford discovered nucleus. Lavoisier also named oxygen and hydrogen and established the role of oxygen in combustion.
Explanation:
The modern periodic law states that the physical and chemical properties of elements are periodic functions of their atomic numbers. This was proposed by Henry Moseley, correcting Mendeleev's periodic table which was based on atomic mass. Atomic number determines the electronic configuration and thus chemical properties.
Explanation:
Calgon is the trade name for sodium hexametaphosphate (Na6P6O18). It is used to soften hard water because the hexametaphosphate ion binds (chelates) with calcium and magnesium ions in the water, forming a soluble complex. This prevents the metal ions from interfering with soap lathering.
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