states-of-matter-quiz-8

States of Matter Quiz-8

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. A flask containing air is heated from 300 K to 500 K. The percentage of air escaped to the atmosphere is nearly

•  40%
•  30%
•  80%
•  60%

Solution
(d) V₁/T₁ =V₂/T₂ V₁/300=V₂/500,V₂=1.66 V Volume escape= 1.66 V-V=0.66 V =66%  

Q2.Which of the following statements is not true about NaCl structure?

•  CI^- ions are in fcc arrangement
•  Na⁺ ions has coordination number 4
•  CI^- ions has coordination number 6
•  Each cell contains 4 NaCl molecules

Solution

(b) In rock salt structure, the coordination number of Na⁺:CI^- is 6 : 6

Q3. If 1 litre of a gas A at 600 mm and 0.5 litre of gas B at 800 mm are taken in a 2 litre bulb. The resulting pressure is: 

•  1500 mm
•  1000 mm
•  2000 mm
•  500 mm

Solution
(d) Use PV=nRT; find n for A and B separately; Now again use PV=nRT for mixture using V=2 litre

Q4. Which has maximum vapour pressure at a given temperature?

•  CH₃ CH₂ CH₂ OH
•  
  
  
•  CH₃-O-CH₃
•  CH₃COOH

Solution
(c) CH₃-O-CH₃ lacks H-bonding hence, it is most volatile, so it has maximum vapour pressure

Q5.The cooling caused by the adiabatic expansion of a compressed gas below its inversion temperature (T_i) without doing external work is called:

•  Joule-Thomson effect
•  Adiabatic demagnetism
•  Tyndall effect
•  Compton effect

Solution
  (a) Whenever, gases are allowed to expand through a small jet under adiabatic conditions, they suffer a change in temperature. This is Joule-Thomson effect. if T>T_i; heating effect if T<T_i; cooling effect  

Q6. Slope between pV and p at constant temperature is

•  Zero
•  1
•  1/2
•  1/√2

Solution
(a) According to Boyle’s law pV=constant The plot of pVagainst p is straight line parallel to x- axis ∴ Slope is zero.  

Q7.A flask is of a capacity one litre. What volume of air will escape out from it on heating from 27℃ to 37℃? Assume pressure constant:

•  1.033 litre
•  33.3 mL
•  33.3 litre
•  None of these

Solution

(b) V₁/T₁ =V₂/T₂ and,then (V₁-V₂ )

Q8.A real gas at high pressure occupies under identical conditions:

•  More volume than that of an ideal gas
•  Less volume than that of an ideal gas
•  Same volume as that of an ideal gas
•  More or less volume than that of an ideal gas depending upon the nature of the gas

Solution
(b) For real gases van der Waals’ pointed out volume correction in gas equation where V was replaced by (V-b).  

Q9.The molecular weight of a gas which diffuse through a porous plug of 1/6th of the speed of hydrogen under identical conditions is:

•  27
•  72
•  36
•  48

Solution

(b) r₁/r₂ =1/6=√([M₂/M₁ ] )=√(2/M) ∴M=72

Q10. The relationship between coefficient of viscosity of a liquid and temperature can be expressed as

•  η=Ae^ERT
•  η=Ae^(E/RT)
•  η=ET/R
•  η=Ae^(RT/E)

Solution

(b) η=Ae^(E/RT)