Metals and Non-Metals — Science STD 10 — Question

A substance added to food containing fats and oils is called:

Identify the name of the reaction. CO₂ + H₂O → C₆H₁₂O₆ + O₂ + H₂O

An element X forms two oxides XO and XO₂. The oxide XO is neutral but XO₂ is acidic in nature. The element X is most likely to be:

Which of the following is a combination reaction?

While cooking, if the bottom of the vessels is getting blackened on the outside, it means that:

Give the ratio in which hydrogen and oxygen are present in water by volume.

The composition of aqua-regia is:

1. Dil.HCl : Conc. HNO₃

3 : 1

2. Conc.HCl : Dil. HNO₃

3 : 1

3. Conc.HCl : Conc.HNO₃

3 : 1

4. Dil.HCl : Dil.HNO₃

3 : 1

The elements whose oxides can turn litmus solution red are:

1. Lithium and sodium.
2. Copper and potassium.
3. Carbon and hydrogen.
4. Phosphorus and sulphur.

If a few drops of a concentrated acid accidentally spills over the hand of a student, what should be done?

1. Wash the hand with saline solution.
2. Wash the hand immediately with plenty of water and apply a paste of sodium hydrogencarbonate.
3. After washing with plenty of water apply solution of sodium hydroxide on the hand.
4. Neutralise the acid with a strong alkali.

An unsaturated hydrocarbon having a triple covalent bond has 50 hydrogen atoms in its molecule. The number of carbon atoms in its molecule will be: