states-of-matter-quiz-9

States of Matter Quiz-9

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. If a vessel containing hydrogen chloride at a pressure p is connected with another vessel of the same volume containing ammonia at a pressure p and the connecting tube opened so that they can mix and form a white solid then the gas pressure

•  Is equal to the pressure p
•  Will be p/p=1
•  Will be doubled, ie,2p
•  Drops to zero

Solution
(d) Drops to zero 

Q2.Which gas may be collected over water?

•  NH₃
•  N₂
•  HCl
•  SO₂

Solution

(b) Rest all are dissolved in water to greater extent.

Q3. During the evaporation of liquid 

•  The temperature of the liquid will rise
•  The temperature of the liquid will fall
•  May rise or fall depending on the nature
•  The temperature remains unaffected

Solution
(b) During evaporation, molecule having high energy leave the surface of liquid. As a result average kinetic energy of liquid decreases. ∵KE∝T ∴ Temperature of liquid falls.

Q4. A gas is heated in such a way so that its pressure and volume both becomes double. Again by lowering temperature, one fourth of initial number of moles of air has been taken in, to maintain the double volume and pressure. By what fraction, the temperature must have been raised finally?

•  1/5 times
•  4/5 times
•  16/5 times
•  8/5 times

Solution

Q5.Which gas when passed through dilute blood will impart a cherry red colour to the solution?

•  CO₂
•  COCl₂
•  NH₃
•  CO

Solution
  (d) CO reacts with red colouring haemoglobin molecules in blood to form a complex of cherry red colour.  

Q6. The molar volume of CO₂ is maximum at

•  NTP
•  0℃ and 2.0 atm
•  127℃ and 1 atm
•  273℃ and 2.0 atm

Solution
(c) pV=nRT V=nRT/p Hence, molar volume of CO₂ is maximum at 127℃ and 1 atm.  

Q7.To raise the volume of a gas by four times, the following method may be adopted. Which of the method is wrong?

•  T is doubled and P is also doubled
•  Keeping P constant, T is raised by four times
•  Temperature is doubled and pressure is halved
•  Keeping temperature constant, pressure is reduced to 1/4 of its initial value

Solution

(a) V∝T/P

Q8.At constant volume, for a fixed number of mole of a gas, the pressure of the gas increases with rise of temperature due to

•  Increase in average molecular speed
•  Increase in number of mole
•  Increase in molecular attraction
•  Decrease in mean free path

Solution
(a) As constant volume, pressure of the gases increases on increasing temperature due to increase in average molecular speed  

Q9.The liquefaction behaviour of temporary gases like CO₂ approaches that of permanent gases like N₂,O₂, etc., as we go:

•  Below critical temperature
•  Above critical temperature
•  Above absolute zero
•  Below absolute zero

Solution

(b) Even CO₂ cannot be liquefied above its critical temperature.

Q10. Hydrogen diffuses six times faster than gas A. The molar mass of gas A is

•  72
•  6
•  24
•  36

Solution

(a) Given, r_{(H2 )}/r_A =6,M_H2=2,M_A=? From Graham’s law of diffusion, r_{(H2 )}/r_A =√(M_A/M_{(H2 )} or 6=√(M_A/2) or 36=M_A/2 ∴ M_A=72