Acids, Bases and Salts — Science STD 10 — Question

To protect tooth decay we are advised to brush our teeth regularly. The nature of the tooth paste commonly used is:

Out of the following pairs of compounds, the unsaturated compounds are:

1. C₂H₆ and C₄H₆
2. C₆H₁₂ and C₅H₁₂
3. C₄H₆ and C₆H₁₂
4. C₂H₆ and C₄H₁₀

The molecular formula of a homologue of butane is:

On pouring sulphuric acid over zinc, which gas is produced?

The pH of a solution is 5.0. Its hydrogen ion concentration is decreased by 100 times, the solution will be:

The element with atomic number 14 is hard and forms acidic oxide and a covalent halide. To which of the following categories does the element belong?

1. Metal.
2. Metalloid.
3. Non-metal.
4. Left-hand side element.

Which of the following are correct structural isomers of butane?

 

1. 1 and 3
2. 2 and 4
3. 1 and 2
4. 3 and 4

A powdered salt (X) in a dry test tube was heated that evolves brown fumes of nitrogen dioxide and a yellow residue of lead oxide is also formed. The salt (X) is:

The element which has the maximum number of valence electrons is:

1. Na.
2. P.
3. Si.
4. Al.