Back to Some Basic Concepts of Chemistry

Set 5 of 14 · Questions 121-150 of 392

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher

Mere Teacher · Previous Year Questions

JEE Main Chemistry · Some Basic Concepts of Chemistry · Set 5 (Q121-150)

QR code to mereteacher.com

Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.

  1. 121.
    Which of the following rules regarding the significant figures and calculations involving them is not correct?
    1. (1)The result of an addition or subtraction is reported to the same number of decimal places as present in number with least decimal places.
    2. (2)Result of multiplication or division should have same number of significant figures as present in most precise figure.
    3. (3)The result of multiplication or division should be rounded off to same number of significant figure as present in least precise figure.
    4. (4)The non-significant figures in the measurements are rounded off.
  2. 122.
    2M of 100 ml is mixed with 3M of 100 ml NaCl solution and 1M of 200 ml solution. Then the ratio of the concentration of cation and anion.
    1. (1)1/2
    2. (2)2
    3. (3)1.5
    4. (4)1
  3. 123.
    of oxalic acid completely neutralised of sodium hydroxide. Molarity of the oxalic acid solution is
    1. (1)0.064
    2. (2)0.045
    3. (3)0.015
    4. (4)0.032
  4. 124.
    For the following reaction the mass of water produced from 445 g of is :
    1. (1)490 g
    2. (2)445 g
    3. (3)495 g
    4. (4)890 g
  5. 125.
    Equal masses of and methane have been taken in a container of volume at temperature in identical conditions. The ratio of the volumes of gases : methane would be
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  6. 126.
    can react with in presence of a catalyst to form as per the following reaction, . The amount of in grams required to produce 50 grams of is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  7. 127.
    Volume of obtained by the complete decomposition of 9.85 of is
    1. (1)2.24
    2. (2)1.12
    3. (3)0.84
    4. (4)0.56
  8. 128.
    Among (each) of the following elements, which one will have the highest number of atoms?
    Element: and Pt
    1. (1)Pr
    2. (2)Pt
    3. (3)Po
    4. (4)Pb
  9. 129.
    50 mL of 0.5 M oxalic acid is needed to neutralize 25 mL of sodium hydroxide solution. The amount of NaOH in 50 mL of the given sodium hydroxide solution is:
    1. (1)10 g
    2. (2)40 g
    3. (3)80 g
    4. (4)none
  10. 130.
    What is number of atoms present in at STP?
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  11. 131.
    Ratio of and of a gas ‘X’ is 1.4. The number of atoms of the gas ‘X’ present in 11.2litres of it at NTP will be
    1. (1)
    2. (2)
    3. (3)3.
    4. (4)2.
  12. 132.
    How many moles of ammonia are produced by 5 moles of hydrogen?
    1. (1)2.3
    2. (2)8.3
    3. (3)10.3
    4. (4)3.3
  13. 133.
    of in acidic medium oxidizes a sample of gas to sulphur. Volume of required to oxidize the same amount of gas to sulphur, in acidic medium is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  14. 134.
    Density of a 2.05M solution of acetic acid in water is 1.02 g/ml. The molality of the solution is:
    1. (1)1.14 mol
    2. (2)3.28 mol
    3. (3)2.28 mol
    4. (4)0.44 mol
  15. 135.
    Concentrated nitric acid is labelled as by mass. The volume in mL of the solution
    which contains 30 g of nitric acid is . Given: Density of nitric acid solution is .
    1. (1)40
    2. (2)32
    3. (3)45
    4. (4)55
  16. 136.
    The amount of solution of hydrochloric acid required to react with of would be
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  17. 137.
    What volume (in ml) of 0.2 M solution should be mixed with the 40 ml of 0.1 M NaOH solution such that the resulting solution has the concentration of as M.
    1. (1)70
    2. (2)45
    3. (3)30
    4. (4)58
  18. 138.
    A solution of sodium sulfate contains 92 g of ions per kilogram of water. The molality of  ions in that solution in molk is:
    1. (1)12
    2. (2)4
    3. (3)8
    4. (4)16
  19. 139.
    The right option for the mass of produced by heating 20 g of pure limestone is (Atomic mass of )
    1. (1)1.32 g
    2. (2)1.12 g
    3. (3)1.76 g
    4. (4)2.64 g
  20. 140.
    Complete combustion of 1.80 g of an oxygen containing compound gave 2.64 g of and1.08 g of . The percentage of oxygen in the organic compound is:
    1. (1)63.53
    2. (2)53.33
    3. (3)51.63
    4. (4)50.33
  21. 141.
    The highest number of helium atoms is in
    1. (1)4 mol of helium
    2. (2)4 u of helium
    3. (3)4 g of helium
    4. (4)2.271098 L of helium at STP
  22. 142.
    An organic compound contains , and . Its emperical formula is
    1. (1)
    2. (2)
    3. (3)
    4. (4)
  23. 143.
    The number of water molecules is maximum in
    1. (1)1.8 gram of water
    2. (2)18 grams of water
    3. (3)18 moles of water
    4. (4)18 molecules of water.
  24. 144.
    The molarity of a solution obtained by mixing 750 mL of 0.5(M) HCl with 250 mL of 2(M)HCl will be:
    1. (1)0.875 M
    2. (2)1.00 M
    3. (3)1.75 M
    4. (4)0.975 M
  25. 145.
    The volume of hydrogen liberated at STP by treating 2.4 g of magnesium with excess of hydrochloric acid is......x L. Given Molar volume of gas is 22.4 L at STP. Molar mass of magnesium is 24 g
  26. 146.
    A compound X with molar weight of 80 g is dissolved in a solvent having density of 0.4 g . Assuming no change in volume upon dissolution, the molality of a 3.2 molar solution is
  27. 147.
    Number of moles of methane required to produce after combustion is moles. The value of is
  28. 148.
    When 10 mL of an aqueous solution of KMnO4 was titrated in acidic medium, equal volume of 0.1 M of an aqueous solution of ferrous sulphate was required for complete discharge of colour. The strength of KMnO4in grams per liter is ____ ×10−2. (Nearest integer) [Atomic mass of ]
  29. 149.
    Geraniol, a volatile organic compound, is a component of rose oil. The density of the vapour is 0.46 at 257°C and 100 mm Hg. The molar mass of geraniol is___________(Nearest Integer)
    [Given R = 0.082 L atm ]
  30. 150.
    A 1.84 mg sample of polyhydric alcoholic compound 'X' of molar mass 92.0 g/mol gave 1.344 mL of gas at STP. The number of alcoholic hydrogens present in compound 'X' is____.