Questions

Ionic character depends on the electronegativity difference between the bonding elements. The greatest the elctronegativity diffference the greatest the ionic character.

Here in the given options, H-F has has the greatest ionic character. The electronegativity of Hydrogen is 2.1 and that of Fluorine is 4. Now the electronegativity difference is 4 - 2.1 = 1.9.

Towel gets wetter and wetter the more it dries because we use that towel which is dried after used.

First Jim and Jeanne walks across the bridge, it takes 2 minutes. 

Jim walks back with the torch light, which takes 1 minute. 

Then Louis and Anne walk on the bridge, which takes 10 minutes.

Jeanne comes back with the torch light, it takes 2 minutes.

Finally Jim and Jeanne walks across the bridge, which takes 2 minutes.

Total = 2 + 1 + 10 + 2 + 2 = 17 minutes

Nitrous acid act as an oxidising agent because it oxidises potassium iodide to iodine. It is also a reducing agent because it decolourises acidified potassium permanganate solution.

Nitric acid acts only as an oxidising agent

Ammonia acts only as a reducing agent

Nitrogen peroxide acts only as an oxidising agent.