The catalyst used in the Ostwald process for nitric acid manufacture is: MCQ with Answer and Explanation

Explanation:
Biogas is produced from anaerobic digestion of organic waste (cow dung, agricultural residue) and is renewable. Mainly methane and CO₂. Coal, petroleum, and natural gas are fossil fuels formed over millions of years, non-renewable. Biogas plants generate clean fuel and also produce enriched manure. Charcoal is also not a fossil fuel; it's from wood pyrolysis.

Explanation:
Catalysts provide an alternative pathway with lower activation energy, increasing reaction rate without being consumed. They do not affect equilibrium constant or thermodynamic parameters (ΔH, ΔS). They can be solid (heterogeneous), liquid, or gas. Enzymes are liquid-phase catalysts. A catalyst does not change the position of equilibrium, only speeds up attainment.

Explanation:
Marie Curie, along with her husband Pierre, conducted pioneering research on radioactivity (a term she coined). In 1898, they discovered two new radioactive elements: polonium (named after her native Poland) and radium. She was the first woman to win a Nobel Prize and the only person to win in two different scientific fields (Physics and Chemistry).