Carbon and its Compounds — Science STD 10 — Question

What is the composition of bio-gas?

If current flows through two lamps arranged: (a) in series, (b) in parallel, and the filament of one lamps breaks, what happens to the other lamp ? Explain your answer.

Write the balanced chemical equation for the following reaction and identify the type of reaction.
Nitrogen gas is treated with hydrogen gas in the presence of a catalyst at 773K to form ammonia gas.

Draw ray diagrams showing the image formation by a concave mirror when an object is placed:A little beyond centre of curvature of the mirror.

Plaster of Paris should be stored in a moisture-proof container. Explain why?

Explain why:
Ionic compounds have generally high melting points.

What were the limitations of Döbereiner’s classification?

Explain giving example where active involvement of local people lead to efficient management of forest.

A piece of thread was tied tightly around an animal's pancreatic duct. The animal subsequently had difficulty in digesting food but did not get diabetes. Explain.

Identify the organisms from the following food chain which will respectively have a maximum and minimum concentration of chemicals in its body? Peacock, frog, snake, grasshopper.