Quiz - chemistry - Some Basic Concepts of Chemistry-PYQ

Q1. The dimensions of pressure are the same as that of Source: orcusprep.in

1995

easy

force per unit volume

energy per unit volume

force

energy

Q2. Given the numbers : 161 cm, 0.161 cm, 0.0161 cm. The number of significant figures for the three numbers is Source: orcusprep.in

1998

easy

3, 3 and 4 respectively

3, 4 and 4 respectively

3, 4 and 5 respectively

3, 3 and 3 respectively.

Q3. Equal masses of H2, O2 and methane have been taken in a container of volume V at temperature 27 ° C in identical conditions. The ratio of the volumes of gases H2 : O2 : methane would be Source: orcusprep.in

NEET 2014

medium

8 : 16 : 1

16 : 8 : 1

16 : 1 : 2

8 : 1 : 2

Q4. What volume of oxygen gas (O2) measured at 0° C and 1 atm, is needed to burn completely 1 L of propane gas (C3H8) measured under the same conditions? Source: orcusprep.in

NEET 2008

easy

5 L

10 L

7 L

6 L

Q5. 0.24 g of a volatile gas, upon vaporisation, gives 45 mL vapour at NTP. What will be the vapour density of the substance? (Density of H2 = 0.089 g/L) Source: orcusprep.in

NEET 1996

medium

95.93

59.93

95.39

5.993

Q6. The molecular weight of O2 and SO2 are 32 and 64 respectively. At 15° C and 150 mmHg pressure, one litre of O2 contains ‘N’ molecules. The number of molecules in two litres of SO2 under the same conditions of temperature and pressure will be Source: orcusprep.in

NEET 1990

easy

N/2

N

2 N

4 N

Q7. What is the weight of oxygen required for the complete combustion of 2.8 kg of ethylene? Source: orcusprep.in

NEET 1989

medium

2.8 kg

6.4 kg

9.6 kg

96 kg

Q8. An element, X has the following isotopic composition : 200X : 90% 199X : 8.0% 202X : 2.0%. The weighted average atomic mass of the naturally occurring element X is closest to Source: orcusprep.in

NEET 2007

medium

201 amu

202 amu

199 amu

200 amu

Q9. Boron has two stable isotopes, 10B(19%) and 11B(81%). Calculate average at. wt. of boron in the periodic table. Source: orcusprep.in

NEET 1990

easy

10.8

10.2

11.2

10.0

Q10. Which one of the followings has maximum number of atoms? Source: orcusprep.in

NEET 2020

medium

1 g of Ag(s) [Atomic mass of Ag = 108]

1 g of Mg(s) [Atomic mass of Mg = 24]

1 g of O2(g) [Atomic mass of O = 16]

1 g of Li(s) [Atomic mass of Li = 7]

Q11. In which case is number of molecules of water maximum? Source: orcusprep.in

NEET 2018

medium

18 mL of water

0.18 g of water

0.00224 L of water vapours at 1 atm and 273 K

10–3 mol of water

Q12. Suppose the elements X and Y combine to form two compounds XY2 and X3Y2. When 0.1 mole of XY2 weighs 10 g and 0.05 mole of X3Y2 weighs 9 g, the atomic weights of X and Y are. Source: orcusprep.in

NEET 2016

hard

40, 30

60, 40

20, 30

30, 20

Q13. If Avogadro number \( \text{N}_A \), is changed from \( 6.022 \times 10^{23} \text{ mol}^{-1} \) to \( 6.022 \times 10^{20} \text{ mol}^{-1} \), this would change Source: orcusprep.in

2015

easy

the mass of one mole of carbon

the ratio of chemical species to each other in a balanced equation

the ratio of elements to each other in a compound

the definition of mass in units of grams.

Q14. The number of water molecules is maximum in Source: orcusprep.in

NEET 2015

easy

1.8 gram of water

18 gram of water

18 moles of water

18 molecules of water.

Q15. A mixture of gases contains \( \text{H}_2 \) and \( \text{O}_2 \) gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture? Source: orcusprep.in

NEET 2015, Cancelled

medium

16 : 1

2 : 1

1 : 4

4 : 1

Q16. Which has the maximum number of molecules among the following? Source: orcusprep.in

NEET Mains 2011

medium

44 g CO2

48 g O3

8 g H2

64 g SO2

Q17. The number of atoms in 0.1 mol of a triatomic gas is (\( \text{N}_A = 6.02 \times 10^{23} \text{ mol}^{-1} \)) Source: orcusprep.in

NEET 2010

easy

\( 6.026 \times 10^{22} \)

\( 1.806 \times 10^{23} \)

\( 3.600 \times 10^{23} \)

\( 1.800 \times 10^{22} \)

Q18. The maximum number of molecules is present in Source: orcusprep.in

NEET 2004

medium

15 L of H2 gas at STP

5 L of N2 gas at STP

0.5 g of H2 gas

10 g of O2 gas.

Q19. Which has maximum molecules? Source: orcusprep.in

NEET 2002

medium

7 g N2

2 g H2

16 g NO2

16 g O2

Q20. Specific volume of cylindrical virus particle is \( 6.02 \times 10^{-2} \) cc/g whose radius and length are 7 Å and 10 Å respectively. If \( \text{N}_A = 6.02 \times 10^{23} \), find molecular weight of virus. Source: orcusprep.in

NEET 2001

hard

15.4 kg/mol

\( 1.54 \times 10^{4} \) kg/mol

\( 3.08 \times 10^{4} \) kg/mol

\( 3.08 \times 10^{3} \) kg/mol

Q21. The number of atoms in 4.25 g of NH3 is approximately Source: orcusprep.in

NEET 1999

medium

\( 4 \times 10^{23} \)

\( 2 \times 10^{23} \)

\( 1 \times 10^{23} \)

\( 6 \times 10^{23} \)

Q22. Haemoglobin contains 0.334% of iron by weight. The molecular weight of haemoglobin is approximately 67200. The number of iron atoms (Atomic weight of Fe is 56) present in one molecule of haemoglobin is Source: orcusprep.in

NEET 1998

medium

4

6

3

2

Q23. The number of moles of oxygen in one litre of air containing 21% oxygen by volume, under standard conditions, is Source: orcusprep.in

NEET 1995

easy

0.0093 mol

2.10 mol

0.186 mol

0.21 mol

Q24. The total number of valence electrons in 4.2 g of N3– ion is (NA is the Avogadro’s number) Source: orcusprep.in

NEET 1994

medium

2.1 NA

4.2 NA

1.6 NA

3.2 NA

Q25. The number of gram molecules of oxygen in \( 6.02 \times 10^{24} \) CO molecules is Source: orcusprep.in

NEET 1990

medium

10 g molecules

5 g molecules

1 g molecule

0.5 g molecules.

Q26. Ratio of \( C_p \) and \( C_v \) of a gas ‘X’ is 1.4. The number of atoms of the gas ‘X’ present in 11.2 litres of it at NTP will be Source: orcusprep.in

NEET 1989

medium

\( 6.02 \times 10^{23} \)

\( 1.2 \times 10^{23} \)

\( 3.01 \times 10^{23} \)

\( 2.01 \times 10^{23} \)

Q27. The number of oxygen atoms in 4.4 g of CO2 is Source: orcusprep.in

NEET 1989

medium

\( 1.2 \times 10^{23} \)

\( 6 \times 10^{22} \)

\( 6 \times 10^{23} \)

\( 12 \times 10^{23} \)

Q28. 1 cc \( \text{N}_2\text{O} \) at NTP contains Source: orcusprep.in

NEET 1988

hard

\( 1.8 \times 10^{22} \) atoms

\( 6.02 \times 10^{23} / 22400 \) molecules

\( 1.32 \times 10^{23} \) electrons

all of the above.

Q29. An organic compound contains carbon, hydrogen and oxygen. Its elemental analysis gave C, 38.71\% and H, 9.67\%. The empirical formula of the compound would be Source: orcusprep.in

NEET 2008

medium

CHO

CH4O

CH3O

CH2O

Q30. Percentage of Se in peroxidase anhydrous enzyme is 0.5\% by weight (at. wt. = 78.4) then minimum molecular weight of peroxidase anhydrous enzyme is Source: orcusprep.in

NEET 2001

medium

\( 1.568 \times 10^{4} \)

\( 1.568 \times 10^{3} \)

15.68

\( 2.136 \times 10^{4} \)

Q31. Which of the following fertilizers has the highest nitrogen percentage? Source: orcusprep.in

NEET 1993

medium

Ammonium sulphate

Calcium cyanamide

Urea

Ammonium nitrate

Q32. The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is Source: orcusprep.in

NEET 2019

easy

40

10

20

30

Q33. The density of 2 M aqueous solution of NaOH is 1.28 g/cm\(^{3}\). The molality of the solution is [Given that molecular mass of NaOH = 40 g mol\(^{-1}\)] Source: orcusprep.in

Odisha NEET 2019

hard

1.20 m

1.56 m

1.67 m

1.32 m

Q34. A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. \( \text{H}_2\text{SO}_4 \). The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be Source: orcusprep.in

NEET 2018

hard

1.4

3.0

2.8

4.4

Q35. What is the mass of the precipitate formed when 50 mL of 16.9\% solution of \( \text{AgNO}_3 \) is mixed with 50 mL of 5.8\% NaCl solution? Source: orcusprep.in

NEET 2015

hard

3.5 g

7 g

14 g

28 g

Q36. 20.0 g of a magnesium carbonate sample decomposes on heating to give carbon dioxide and 8.0 g magnesium oxide. What will be the percentage purity of magnesium carbonate in the sample? (At. wt. of Mg = 24) Source: orcusprep.in

NEET 2015

medium

96

60

84

75

Q37. When 22.4 litres of \( \text{H}_2(g) \) is mixed with 11.2 litres of \( \text{Cl}_2(g) \), each at STP, the moles of \( \text{HCl}(g) \) formed is equal to Source: orcusprep.in

NEET 2014

easy

1 mol of HCl(g)

2 mol of HCl(g)

0.5 mol of HCl(g)

1.5 mol of HCl(g)

Q38. 1.0 g of magnesium is burnt with 0.56 g \( \text{O}_2 \) in a closed vessel. Which reactant is left in excess and how much? (At. wt. Mg = 24, O = 16) Source: orcusprep.in

NEET 2014

medium

Mg, 0.16 g

\( \text{O}_2 \), 0.16 g

Mg, 0.44 g

\( \text{O}_2 \), 0.28 g

Q39. \( 6.02 \times 10^{20} \) molecules of urea are present in 100 mL of its solution. The concentration of solution is Source: orcusprep.in

NEET 2013

medium

0.001 M

0.1 M

0.02 M

0.01 M

Q40. In an experiment it showed that 10 mL of 0.05 M solution of chloride required 10 mL of 0.1 M solution of \( \text{AgNO}_3 \), which of the following will be the formula of the chloride (X stands for the symbol of the element other than chlorine)? Source: orcusprep.in

Karnataka NEET 2013

hard

\( \text{X}_2\text{Cl}_2 \)

\( \text{XCl}_2 \)

\( \text{XCl}_4 \)

\( \text{X}_2\text{Cl} \)

Q41. 25.3 g of sodium carbonate, \( \text{Na}_2\text{CO}_3 \) is dissolved in enough water to make 250 mL of solution. If sodium carbonate dissociates completely, molar concentration of sodium ion, \( \text{Na}^+ \) and carbonate ions, \( \text{CO}_3^{2-} \) are respectively (Molar mass of \( \text{Na}_2\text{CO}_3 \) = 106 g mol\(^{-1}\)) Source: orcusprep.in

NEET 2010

medium

0.955 M and 1.910 M

1.910 M and 0.955 M

1.90 M and 1.910 M

0.477 M and 0.477 M

Q42. 10 g of hydrogen and 64 g of oxygen were filled in a steel vessel and exploded. Amount of water produced in this reaction will be Source: orcusprep.in

NEET 2009

medium

3 mol

4 mol

1 mol

2 mol

Q43. In the reaction,
\( 4\text{NH}_3(g) + 5\text{O}_2(g) \rightarrow 4\text{NO}(g) + 6\text{H}_2\text{O}(l) \)
when 1 mole of ammonia and 1 mole of \( \text{O}_2 \) are made to react to completion Source: orcusprep.in

NEET 1998

medium

all the oxygen will be consumed

1.0 mole of NO will be produced

1.0 mole of \( \text{H}_2\text{O} \) is produced

all the ammonia will be consumed.

Q44. The amount of zinc required to produce 224 mL of \( \text{H}_2 \) at STP on treatment with dilute \( \text{H}_2\text{SO}_4 \) will be Source: orcusprep.in

NEET 1996

easy

65 g

0.065 g

0.65 g

6.5 g

Q45. At STP the density of \( \text{CCl}_4 \) vapour in g/L will be nearest to Source: orcusprep.in

NEET 1988

medium

6.87

3.42

10.26

4.57

Q46. How many moles of lead(II) chloride will be formed from a reaction between 6.5 g of PbO and 3.2 g HCl? Source: orcusprep.in

NEET 2008

medium

0.011

0.029

0.044

0.333

Q47. The mass of carbon anode consumed (giving only carbon dioxide) in the production of 270 kg of aluminium metal from bauxite by the Hall process is (Atomic mass : Al = 27) Source: orcusprep.in

NEET 2005

hard

270 kg

540 kg

90 kg

180 kg

Q48. Molarity of liquid HCl, if density of solution is 1.17 g/cc is Source: orcusprep.in

NEET 2001

hard

36.5

18.25

32.05

42.10

Q49. Volume of \( \text{CO}_2 \) obtained by the complete decomposition of 9.85 g of \( \text{BaCO}_3 \) is Source: orcusprep.in

NEET 2000

medium

2.24 L

1.12 L

0.84 L

0.56 L

Q50. One mole of carbon atom weighs 12 g, the number of atoms in it is equal to,
(Mass of carbon – 12 is 1.9926 × 10\(^{-23}\) g) Source: orcusprep.in

NEET (UG) 2020 (COVID-19)

easy

\( 1.2 \times 10^{23} \)

\( 6.022 \times 10^{22} \)

\( 12 \times 10^{22} \)

\( 6.022 \times 10^{23} \)

Q51. An organic comopound contains 78% (by wt.) carbon and remaining percentage of hydrogen. The right option for the empirical formula of this compound is [Atomic wt. of C is 12, H is 1] Source: orcusprep.in

NEET (UG) 2021

medium

CH

CH\(_2\)

CH\(_3\)

CH\(_4\)

Q52. An organic compound on analysis gave C = 54.5%, H = 9.1% by mass. Its empirical formula is Source: orcusprep.in

NEET (UG) 2021 (Paper-2)

medium

CHO\(_2\)

CH\(_2\)O

C\(_2\)H\(_4\)O

C\(_3\)H\(_4\)O

Q53. If 1 mL of water contains 20 drops then number of molecules in a drop of water is Source: orcusprep.in

not-set

medium

\( 6.023 \times 10^{23} \)

\( 1.673 \times 10^{21} \)

\( 1.344 \times 10^{18} \)

\( 4.346 \times 10^{20} \)

Q54. A sample of phosphorous trichloride (\( \text{PCl}_3 \)) contains 1.4 moles of the substance. How many atoms are there in the sample? Source: orcusprep.in

not-set

medium

4

5.6

\( 8.431 \times 10^{23} \)

\( 3.372 \times 10^{24} \)

Q55. In one molal solution that contains 0.5 mole of a solute, there is Source: orcusprep.in

NEET (UG) 2022

easy

500 g of solvent

100 mL of solvent

1000 g of solvent

500 mL of solvent

Q56. What mass of 95% pure \( \text{CaCO}_3 \) will be required to neutralise 50 mL of 0.5 M HCl solution according to the following reaction ?
\( \text{CaCO}_3(s)+ 2\text{HCl}(aq) \rightarrow \text{CaCl}_2(aq) + \text{CO}_2(g) + \text{H}_2\text{O}(l) \)
[Calculate upto second place of decimal point] Source: orcusprep.in

not-set

hard

1.32 g

3.65 g

9.50 g

1.25 g

Q57. Match List-I with List-II :

List-I
(a) 4.48 litres of \( \text{O}_2 \) at STP
(b) \( 12.022 \times 10^{22} \) molecules of \( \text{H}_2\text{O} \)
(c) 96 g of \( \text{O}_2 \)
(d) 88 g of \( \text{CO}_2 \)

List-II
(i) 0.2 moles
(ii) \( 12.044 \times 10^{23} \) molecules
(iii) 6.4 g
(iv) 67.2 litres at STP

(Given – Molar volume of a gas at STP = 22.4 L)
Choose the correct answer from the options given below : Source: orcusprep.in

NEET (UG) 2022 (OVERSEAS)

medium

(a)-(iii), (b)-(i), (c)-(iv), (d)-(ii)

(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)

(a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)

(a)-(i), (b)-(iii), (c)-(iv), (d)-(ii)

Q58. The density of the solution is 2.15 g mL\(^{-1}\), then mass of 2.5 mL solution in correct significant figures is Source: orcusprep.in

Re-NEET (UG) 2022

easy

\( 5375 \times 10^{-3} \) g

5.4 g

5.38 g

53.75 g

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Chemistry - Some Basic Concepts of Chemistry-PYQ

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Chemistry - Some Basic Concepts of Chemistry-PYQ

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