Chemistry

Sodium and chlorine are reacted, and as a result, sodium chloride is formed, which is also called table salt. What option gives the reactants and products of the reaction?

• Reactants – sodium; products – chlorine

• Reactants – sodium and table salt; products – chlorine

• Reactants – tables salt; products – sodium and chlorine

• Reactants – sodium and chlorine; products – sodium chloride

In the double displacement reaction between aqueous potassium iodide and aqueous lead nitrate, a yellow precipitate of lead iodide is formed. While performing the activity if lead nitrate is not available, which of the following can be used in place of lead nitrate?

• Lead sulphate (insoluble)

• Lead acetate

• Ammonium nitrate

• Potassium sulphate

In which of the following chemical equations, the abbreviations represent the correct states of the reactants and products involved at reaction temperature?

• 2H2 (l) + O2 (l) > 2H2O(g)

• 2H2 (g) + O2 (l) > 2H2O (l)

• 2H2 (g) + O2 (g) > 2H2O (l)

• 2H2 (g) +O2 (g) > 2H2O (g)

When a plane mirror is rotated through a certain angle, the reflected ray turns through twice as much and the size of the image:

• is doubled

• is halved

• becomes infinite

• remains the same

If an object is placed symmetrically between two plane mirrors, inclined at an angle of 72 degrees, then the total no. of images formed is:

• 5

• 4

• 2

• Infinite

The focal length of a plane mirror is

• 0

• Infinite

• 25cm

• -25cm

The image shows the path of incident rays to a concave mirror.

Where would the reflected rays meet for the image formation to take place?

• Behind the mirror

• Between F and O

• Between C and F

• Beyond C

Which one of the following salts does not con-tain water of crystallisation?

• Blue vitriol

• Baking soda

• Washing soda

• Gypsum

At what temperature is gypsum heated to form Plaster of Paris

• 90°C

• 110°C

• 100°C

• 120°C

The apparatus given in the adjoining figure was set up to demonstrate electrical conductivity.

Which of the following statement(s) is (are) correct?

1. Bulb will not glow because electrolyte is not acidic.

2. Bulb will glow because HCl is a strong acid and furnishes ions for conduction.

3. Bulb will not glow because circuit is incomplete.

4. Bulb will not glow because it depends upon the type of electrolytic solution.

• (i) and (iii)

• (ii) and (iv)

• (ii) only

• (iv) only