MODEL PAPER - 7 [2026] — Science STD 10 — Question

While studying the saponification reaction, what do you observe when you mix an equal amount of colourless vegetable oil and 20% aqueous solution of NaOH in a beaker?

Carbon forms four covalent bonds by sharing its four valence electrons with four univalent atoms, e.g. hydrogen. After the formation of four bonds, carbon attains the electronic configuration of:

1. Helium.
2. Neon.
3. Argon.
4. Krypton.

The salt whose aqueous solution will turn blue litmus to red is:

1. Ammonium sulphate.
2. Sodium acetate.
3. Sodium chloride.
4. Potassium carbonate.

Which one of the following metals do not react with cold as well as hot water?

1. Na.
2. Ca.
3. Mg.
4. Fe.

Which of the following can be used in the laboratory to test whether a solution is a base or an acid?

Chemically rust is:

Which of the following property is generally not shown by metals?

The formula of baking soda is:

Manganese metal is extracted from manganese dioxide by a reduction process by making use of:

1. Carbon.
2. Hydrogen.
3. Electrolysis.
4. Aluminium.

Property of metals by which they can be beaten in to thin sheets is called: