What is the number of octahedral and tetrahedral voids presents respectively in 0.25 mole of a substance having hcp structure?

For a reaction $$\mathrm{A} \rightarrow$$ product, rate constant is $$2 \times 10^{-2} \mathrm{~s}^{-1}$$. The initial concentration of $$\mathrm{A}$$ is 1.0 mol dm$${ }^{-3}$$. What is the value of $$\log \frac{1}{[\mathrm{~A}]_{\mathrm{t}}}$$ after 100 seconds?

When tert-butyl bromide is heated with silver fluoride, the major product obtained is

What are the final products obtained by ozonolysis of propene?