91.

The number of moles in 128 gm of SO₂ will be

• 1 mole

• 2 mole

• 3 mole

• 4 mole

The oxidation state of iron in Fe(CO)₅ is

• 0

• 2

• 3

• 5

The compound responsible for the temporary hardness of water is

• Mg(HCO₃)₂

• CaCl₂

• MgSO₄

• CaCO₃

Medium A is optically denser than Medium B. Which one of the following statements is true?

• Speed of light is same in both A and B

• Cannot be compared

• Speed of light is more in medium A than in medium B

• Speed of light is more in medium B than in medium A

Heat energy of an object is

• the average energy of the molecules of the object

• the total energy of the molecules of the object

• the average velocity of the molecules of the object

• the average potential energy of the molecules of the object

The momentum of a heavy object at rest will be

• zero

• small

• large

• None of these

The heating element in an electric iron is made of

• iron

• tungsten

• nichrome

• copper

Emission of which one of the following will produce isobars?

• Alpha particles

• Beta particles

• Gamma rays

• X-rays

The radioactive isotope of hydrogen is called

• deuterium

• protium

• radium

• tritium

Vapour pressure of liquid depends upon the

• quantity of heat

• temperature of liquid

• specific heat of liquid

• density of liquid