Which of the following substances sublimes upon heating?

Which of the following pairs of elements might form an alloy?

Name a suitable technique of separation of the components from a mixture of calcium sulphate and camphor.

Two liquids $(A)$ and $(B)$ can be separated by the method of fractional distillation. The boiling point of liquid $(A)$ is less than the boiling point of liquid $(B)$. Which of the liquids do you expect to come out first in the distillate? Explain.

One sample of atmospheric air is found to have $0.03\%$ of carbon dioxide and another sample $0.04\%$. This is evidence that

Which is the best method to separate a mixture of benzoic acid and naphthalene?