Chemistry 1st Half Book Test

1 / 12th of the mass of one carbon atom is called

• Mass number

• Atomic weight

• Relative atomic mass

• Atomic mass unit

How many atoms of carbon are present in 90 g of glucose

• 6.02 × 10²³

• 1.80 × 10²³

• 3.01× 10²³

• 1.80 × 10²⁴

The volume occupied by 3.2g of O₂ at STP

• 2.24 dm³

• 22.4 dm³

• 1.12 dm³

• 2.24 cm³

• 1 mole of NH₃ will produce 6 moles of N₂

• For the complete reaction, 2 moles of NH₃, 40g of O₂ are required

• For the complete reaction, 2 moles of NH₃, 20g of O₂ are required

• It shows that 1 mole of NH₃ will produce 1/2 mole of N₂

Which of the following has least mass

• 1 mole of nitrogen gas

• 1 mole Neon gas

• 1 mole sulphur

• 3 × 10²³ atoms of C

An ideal gas has a volume of V at 2 atm pressure keeping temperature of the gas constant, its pressure is doubled. The volume of gas will become

• V

• 0.5 V

• 2V

• 4V

All of the given types of enthalpy changes are either endothermic or exothermic. Select the one which can be endothermic as well as exothermic

• Enthalpy of combustion

• Enthalpy of ionization

• Enthalpy of formation

• Enthalpy of atomization

To cook the food at a high mountain is difficult as compared to at sea level the reason is that

• The temperature at the top of the mountain is low

• The density of water decreases at the mountains

• The hydrogen bonding in water changes with the change of height

• The boiling point of water decreases at the mountain

NaCl is face centered cubic structure in which Na⁺ ion at each face of unit cell is shared by

• 4–unit cell

• 2– unit cell

• Only one unit cell

• 8–unit cell

The vapour pressure of a liquid remains constant

• By increasing temperature

• By decreasing external pressure

• By increasing amount of liquid

• By decreasing force of attraction