states-of-matter-quiz-2

States of Matter Quiz-2

Dear Readers,

The one subject in NEET which is candidates who can easily attain good marks is Chemistry. That's the reason, often, one doesn’t pay notice and choose to compromise it. But if one wants to rank above others, the tip is to be thorough with NEET chemistry concepts. The understanding of reactions and definite basic understanding is what requires major attention in Chemistry but once done it only gets simpler from there. The main focus on the to-do list should be on getting a hang of the NCERT syllabus of NEET chemistry..

Q1. Crystals can be classified into…. basic crystal lattices

•  3
•  7
•  6
•  14

Solution
(b) 7 

Q2.A preweighted vessel was filled with CO₂ at STP and weighed. It was then evaluated, filled with SO₂ at the same temperature and pressure and again weighted. The weight of the CO₂ will be

•  The same as that of the SO₂
•  Twice of that of the SO₂
•  Half that of the SO₂
•  Two third of that of SO₂

Solution

(c) (M wt.of CO₂)/(M wt.of SO₂ )=M₁/M₂ =44/64=11/16 approx =2/3

Q3. Consider 1 cm³ sample of air at absolute temperature T₀ at sea-level and another 1 cm³ sample of air at a height where the pressure is one third atmosphere. The absolute temperature T of the sample at the height is : 

•  Equal to T₀/3
•  Equal to T₀
•  Equal to 3T₀
•  Cannot be determined in terms of T₀ from the above data

Solution
(d) Mass of the gas is not known.

Q4. A gas of unknown identity effuses at the rate of 83.3 mLs^-1 in an effusion apparatus in which carbon dioxide effuses at the rate of 102 mLs^-1. Calculate molar mass of the unknown gas.

•  6.597 g mol^-1
•  65.97 g mol^-1
•  3.650 g mol^-1
•  36.50 g mol^-1

Solution
(b) r_x/r_CO2 =√(M_CO2/M_x ) 83.3/102=√(M_CO2/M_x )= √(44/M_x ) M_x=44×(102/83.3)² =65.97 g mol^-1

Q5.Graham’s law of diffusion gives better results at:

•  High pressure
•  High temperature
•  Low pressure
•  At all conditions

Solution
  (c) Graham’s law is valid at low pressure.  

Q6. The closest distance between the centres of two molecules of a gas taking part in collision is called

•  Effective molecular diameter
•  Collision diameter
•  Both (a) and (b)
•  None of the above

Solution
(c) Collision diameter or effective molecular diameter is the closest distance between the centre of two molecules of a gas taking part in collision  

Q7.Certain volume of a gas exerts on its walls some pressure at a particular temperature. It has been found that by reducing the volume of the gas to half of its original value the pressure becomes twice that of the initial value at constant temperature. This happens because:

•  Weight of the gas increases with pressure
•  Speed of the gas molecules decreases
•  More number of gas molecules strike the surface per second
•  Gas molecules attract each other

Solution

(c) Collision frequency increases when molecules come closer to each other.

Q8.The circulation of blood in human body supplies O₂ and releases CO₂. The concentration of O₂ and CO₂ is variable but on the average, 100 mL blood contains 0.02 g of O₂ and 0.08 g CO₂. The volume of O₂ and CO₂ at 1 atm and body temperature 37℃, assuming 10 litre blood in human body is:

•  2 litre,4 litre
•  1.5 litre,4.5 litre
•  1.59 litre,4.62 litre
•  3.82 litre,4.62 litre

Solution
(c) ∵100 mL blood has 0.02 g O₂ and 0.08 g CO₂ 10,000 mL blood has 2 g O₂ and 8 g CO₂ using PV=nRT,for O₂  ∶1×V=2/32×0.0821×310 ∴V_O2=1.59 litre For CO₂ ∶1×V=8/44×0.0821×310 V_CO2=4.62 litre      

Q9.Schottky defect in crystals is observed when

•  Density of crystal is increased
•  An ion leaves its normal site and occupies an interstitial site
•  Equal number of cations and anions are missing from the lattice
•  Unequal number of cations and anions are missing from the lattice

Solution

(c) Schottky defect is due to missing of equal number of cations and anions

Q10. In a mixture of a light gas and a heavy gas in a closed container, the light gas will:

•  Have a lower average speed per molecule than the heavy gas
•  Have a higher average speed per molecule than the heavy gas
•  Rise to the top of the container
•  All are wrong

Solution

(b) u_rms=√(3RT/M)