Chemical Reactions and Equations — Science STD 10 — Question

Electrical wires have a coating of an insulting material. The material, generally used is:

1. Sulphur.
2. Graphite.
3. PVC.
4. All can be used.

Bee sting contains:

Element X reacts with element Y to form a compound Z. During the formation of compound Z, atoms of X lose one electron each whereas atoms of Y gain one electron each. Which of the following property is not shown by compound Z?

1. High melting point.
2. Low melting point.
3. Occurrence as solid.
4. Conduction of electricity in molten state.

Where would you locate the element with electronic configuration 2, 8 in the Modern Periodic Table?

1. Group 8.
2. Group 2.
3. Group 18.
4. Group 10.

A student adds a few drops of ethanoic acid to test tubes X, Y and Z containing aqueous solutions of sodium chloride, sodium hydroxide and sodium carbonate respectively. If he now brings a burning splinter near the mouth of the test tubes immediately after adding the ethanoic acid in each one of them, in which of the test tube or test tubes the flame gets extinguished?

You want to test for hardness of water but hard water is not available in the laboratory. Which of the following compounds may be dissolved in pure water to make it hard?
i. Hydrogen Carbonate of Sodium
ii. Sulphate of Magnesium
iii. Chloride of Calcium
iv. Carbonate of Sodium

Which of the following elements would lose an electron easily?

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

For preparing soap in the laboratory we require an oil and a base. Which of the following combinations of an oil and a base would be best suited for the preparation of soap?

Oxidation is a process which involves: