Which of the following has the smallest number of molecules ? fr

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 Multiple Choice QuestionsMultiple Choice Questions

621.

Which has maximum number of atoms ?

  • 24 g of C

  • 56 g of Fe

  • 26 g of Al

  • 108 g of Ag


622.

35.4 ml of HCl is required for the neutralization of a solution containing 0.275 g of sodium hydroxide. The normality of hydrochloric acid is ?

  • 0.97 N

  • 0.142 N

  • 0.194 N

  • 0.244 N


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623.

Which of the following has the smallest number of molecules ?

  • 0.1 mole of CO2 gas

  • 11.2 L of CO2 gas at STP

  • 22 g of CO2 gas

  • 22.4 x 10mL of CO2 gas at STP


A.

0.1 mole of CO2 gas

(a) 0.1 mole of CO2

(b)11.222.4 = 0.5 mole of CO2

(c) 2244 = 0.5 mole of CO2

(d) 22.4 ×10322400= 1 mole of CO2

Hence, the number of moles of CO2 is least ie, 0.1.


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624.

The value of amu is which of the following ?

  • 1.57 × 10-24 kg

  • 1.66 × 10-24 kg

  • 1.99 × 10-23 kg

  • 1.66 × 10-27 kg


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625.

4.6 x 1022 atoms of an element weigh 13.8g. The atomic weight of that element is

  • 290

  • 180

  • 34.4

  • 10.4


626.

2g of mixture of CO and CO2 on reaction with excess I2Oproduced 2.54g of I2. What would be the mass% of CO2 in the original mixture?

  • 60

  • 30

  • 70

  • 35


627.

When 10g of 90% pure lime stone is heated completely, the volume (in litres) of CO2 is liberated at STP is

  • 22.4

  • 2.24

  • 20.16

  • 2.016


628.

Which one of the following has unit positive charge and 1 amu mass ?

  • Electron

  • Neutron

  • Proton

  • None of these


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629.

Law of constant composition is same as the law of

  • conservation of mass

  • conservation of energy

  • multiple proportion

  • definite proportion


630.

By dissolving 5 g substance in 50 g of water, the decrease in freezing point is 1.2°C. The gram molal depression is 1.85°C. The molecular weight of substance is :

  • 105.4

  • 118.2

  • 137.2

  • 154.2


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