Acids, Bases and Salts — Science STD 10 — Question

The pH of a solution is 4.0. What should be the change in the hydrogen ion concentration of the solution, if its pH is to be increased to 5.0.

When sodium hydrogen carbonate is added to ethanoic acid a gas evolves.
Consider the following statements about the gas evolved?
A. It turns lime water milky.
B. It is evolved with a brisk effervescence.
C. It has a smell of burning sulphur.
D. It is also a by-product of respiration.
The correct statements are:

In an ionic compound, cations and anions are held together by:

An acid (A) with sodium hydrogencarbonate is used in making the cakes fluffy and spongy. It is due to the release of (B) gas in the reaction. Here, A and B are:

The daffodil plants grow best in a soil having a pH range of 6.0 to 6.5. If the soil in a garden has a pH of 4.5, which substance needs to be added to the soil in order to grow daffodils?

1. Salt.
2. Lime.
3. Sand.
4. Compost.

When ethanol is heated with concentrated sulphuric acid at 170°C, it gets converted into ethene. In this reaction, concentrated sulphuric acid acts as:

1. Oxidising agent.
2. Catalyst.
3. Dehydrating agent.
4. Reducing agent.

An element X reacts with hydrogen, when heated, to form a covalent hydride H₂X. If H₂X has a smell of rotten eggs, the element X is likely to be:

On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained. What other name can be given to this precipitation reaction?