PYQSide ExamsMy practice

Some Basic Concepts of Chemistry · Question 17

NEET (UG) 2020MCQEasy📈 Topic in 50% papers+4−1
1

Which one of the following has maximum number of atoms?

  1. 1 g of Mg(s) [Atomic mass of Mg = 24]
  2. 1 g of O2(g) [Atomic mass of O = 16]
  3. 1 g of Li(s) [Atomic mass of Li = 7]
  4. 1 g of Ag(s) [Atomic mass of Ag = 108]

Answer

(3) 1 g of Li(s) [Atomic mass of Li = 7]

Solution

Number of atoms = (moles of atoms) × NA, so compare the moles of atoms.

1 g Mg: 124 mol atoms

1 g O2: 132 mol molecules ⇒ 232 = 116 mol atoms

1 g Li: 17 mol atoms

1 g Ag: 1108 mol atoms

∴ 17 is the largest ⇒ 1 g of Li contains the maximum number of atoms ( 17NA ).

Answer: (3)

NEET (UG) 2020

Keep practising — Some Basic Concepts of Chemistry

2

The number of moles of hydrogen molecules required to produce 20 moles of ammonia through Haber’s process is :

  1. 10
  2. 20
  3. 30
  4. 40
NEET (UG) 2019
3

A mixture of 2.3 g formic acid and 4.5 g oxalic acid is treated with conc. H2SO4. The evolved gaseous mixture is passed through KOH pellets. Weight (in g) of the remaining product at STP will be

  1. 1.4
  2. 3.0
  3. 2.8
  4. 4.4
NEET 2018
4

In which case is number of molecules of water maximum?

  1. 18 mL of water
  2. 0.18 g of water
  3. 0.00224 L of water vapours at 1 atm and 273 K
  4. 10-3 mol of water
NEET 2018
5

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

  1. 40, 30
  2. 60, 40
  3. 20, 30
  4. 30, 20
NEET 2016 (Phase 2)
6

What is the mass of the precipitate formed when 50 mL of 16.9\% solution of AgNO3 is mixed with 50 mL of 5.8\% NaCl solution ? (Ag = 107.8, N = 14, O = 16, Na = 23, Cl = 35.5)

  1. 3.5 g
  2. 7 g
  3. 14 g
  4. 28 g
AIPMT 2015
7

If Avogadro number NA, is changed from 6.022 1023 mol-1 to 6.022 1020 mol-1, this would change

  1. the mass of one mole of carbon
  2. the ratio of chemical species to each other in a balanced equation
  3. the ratio of elements to each other in a compound
  4. the definition of mass in units of grams.
AIPMT 2015
8

The number of water molecules is maximum in

  1. 1.8 gram of water
  2. 18 gram of water
  3. 18 moles of water
  4. 18 molecules of water
AIPMT 2015
9

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)

  1. 96
  2. 60
  3. 84
  4. 75
Out of syllabusAIPMT 2015
10

A mixture of gases contains H2 and O2 gases in the ratio of 1 : 4 (w/w). What is the molar ratio of the two gases in the mixture ?

  1. 16 : 1
  2. 2 : 1
  3. 1 : 4
  4. 4 : 1
AIPMT 2015 (Cancelled)
11

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

  1. 8 : 16 : 1
  2. 16 : 8 : 1
  3. 16 : 1 : 2
  4. 8 : 1 : 2
AIPMT 2014

All Some Basic Concepts of Chemistry PYQs →

PDFDownload Some Basic Concepts of Chemistry PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters
Physical ChemistrySome Basic Concepts of ChemistryStructure of AtomStates of MatterThermodynamicsEquilibriumRedox ReactionsSolid StateSolutionsElectrochemistryChemical KineticsSurface Chemistry
Inorganic ChemistryClassification of Elements and Periodicity in PropertiesChemical Bonding and Molecular StructureHydrogens-Block Elementsp-Block Elements (Group 13 & 14)Environmental ChemistryGeneral Principles of Isolation of Elementsp-Block Elements (Group 15–18)d- and f-Block ElementsCoordination Compounds
Organic ChemistryOrganic Chemistry – Some Basic Principles and TechniquesIsomerismHydrocarbonsHaloalkanes and HaloarenesAlcohols, Phenols and EthersAldehydes, Ketones and Carboxylic AcidsAminesBiomoleculesPolymersChemistry in Everyday LifePrinciples Related to Practical Chemistry