Mole concept

Tested in 5 real MPSC questions across 3 years (2015–2021). See it in context on the interactive Concept Graph →

Years it was asked

2021 2019 2015

What you need to know first

Atomic mass unitBasic ChemistryDefinition of moleAtomic weightsBasic chemistry formulasAtomic mass calculationBasic stoichiometry

What mastering this unlocks

Ideal gas lawGas equationsScientific UnitsAtomic mass unitDensity

Real questions that test this

अव्होगाड्रो संख्या ही पुढीलपैकी गोष्टींशी संबंधित असते / The Avogadro number is related to

1)एखाद्या पदार्थाची 10³ मीटर मधील घनता. / Density of a substance in 10³ m

2)कोणत्याही पदार्थाच्या 1 ग्रॅम मधील रेणूसंख्या / Molecules in one gram of any material

3)1 mol मधील कोणत्याही पदार्थाच्या अणुकणांची संख्या / Atomic particles in 1 mol of any substance&check; Correct

4)एखाद्या पदार्थाच्या आण्विक वस्तुमानाची 10³ ग्रॅममधील C-12 मूळद्रव्यातील अणूंशी केलेली तुलना. / Atomic mass of a substance in comparison with 10³ grams of C-12 atoms.

Avogadro's number represents the total number of constituent particles (atoms or molecules) present in exactly 1 mole of any substance.

10 ग्रॅम वायुरूप हायड्रोजनमध्ये H₂, मानक दाब आणि तापमानात हायड्रोजनचे _________ मोल असतात. 10 g of gaseous hydrogen H₂, at NTP/STP contain _________ mol of hydrogen.

1)10

2)5&check; Correct

3)1

4)0.1

Number of moles is calculated as given mass divided by molar mass. Molar mass of H2 is 2 g/mol. So, 10 g / 2 g/mol = 5 moles.

ग्लुकोज मधे कार्बनची टक्केवारी __________ आहे. / The percentage of carbon in glucose is

a)40%&check; Correct

b)53%

c)45%

d)55%

The molecular formula of glucose is C6H12O6. Molar mass = (6*12) + (12*1) + (6*16) = 72 + 12 + 96 = 180 g/mol. Percentage of carbon = (72 / 180) * 100 = 40%.

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