Free MCQs & Online Quiz Practice for Exams

Q: If water samples are taken from sea, river, clouds, lakes or snow, they will be found to contain hydrogen and oxygen in the ratio of 1:8 by weight. This indicates the law of: (Entry test 2006)

A) Definite proportion

B) Multiple proportions

C) Reciprocal proportion

D) None of these

Q: Which one of the following contains the greatest number of atoms? (Entry test 2008)

A) 4g of hydrogen

B) 4g of magnesium

C) 71g of chlorine

D) 127g of iodine

Q: How many moles of NaCl are produced from the reaction of 6.022×10²³? (Entry test 2008)

A) 6.022×10²³ mol

B) 0.5 mol

C) 3.011×10²³ mol

D) 1 mole

Q: If 28.0g of nitrogen gas reacts with 8.0g of hydrogen gas to form ammonia, the limiting reactant among the two will be: (Entry test 2008)

A) N₂

B) H₂

C) Both a & b

D) None

Q: 10L of Cl₂ gas reacts with 40L of H₂ gas under the same conditions of temperature and pressure. How much volume of HCl should be produced? (Entry test 2008)

A) 40L

B) 30L

C) 20L

D) 10L

Q: A gas at STP contains only 6.02×10²³ atoms and is mono-atomic It will occupy: (Entry test 2010)

A) 1.2 L

B) 22.4 L

C) 30.5 L

D) 44.8 L

Q: The combustion of one mole of propane (C₃H₈) produces how many moles of water? (Entry test 2011)

A) 2

B) 3

C) 4

D) 5

Q: How many grams of water are produced in burning 2.24 dm³ of hydrogen at STP? (Entry test 2011)

A) 180 g

B) 81g

C) 1.8g

D) 0.18g

Q: How many hydrogen atoms are present in one mole of water? (Entry test 2012)

A) 1.086×10²⁴

B) 1.204×10²⁴

C) 3.01×10²³

D) 6.02×10²³

Q: The volume occupied by 3.2 g of oxygen at STP is: (Entry test 2012)

A) 22.4 dm³

B) 2.24 dm³

C) 11.2 dm³

D) 16.0 dm³

Q: How many atoms are contained in one mole of Ca(OH)₂? (Entry test 2012)

A) 5×6.02×10²³

B) 30×6.02×10²³

C) 3×6.02×10²³

D) 6×6.02×10²³

Q: One mole is the amount of substance which contains as many elementary entities as contained in: (Entry test 2012)

A) 0.12 kg of ₆C¹²

B) 1.2 kg of ₆C¹²

C) 0.012 kg of ₆C¹²

D) 0.12 kg of ₈O¹⁶

Q: 1 amu is equal to 1.661×10⁻²⁴ g, then 1.0 g will be equal to: (Entry test 2012)

A) 6.02×10²³ amu

B) 6.02×10⁻²³ amu

C) 6.02×10⁻²⁴ amu

D) 6.02×10²⁴ amu

Q: Which gas occupies the largest volume at STP? (Entry test 2013)

A) 16g of CH₄

B) 32g of O₂

C) 4g of H₂

D) 28g of N₂

Q: A sample of carbon-12 has a mass of 3.0 g. Which expression gives the number of atoms in the sample? (Nₐ = Avogadro’s constant) (Entry test 2013)

A) 0.0030Nₐ

B) 0.25Nₐ

C) 3.0Nₐ

D) 4.0Nₐ

Q: How many molecules are present in 0.20 g of hydrogen gas? (Entry test 2013)

A) (0.20×1.008)×6.02x10²³

B) 0.20×2.016

C) (0.20×2.016)x6.02×10²³

D) (0.20×0.70)x6.02×10²³

Q: Choose the correct relation about the percent yield. It is equal to: (Entry test 2014)

A) (actual yield/theoretical yield)×100

B) (theoretical yield/actual yield)×100

C) (actual yield/theoretical yield)×10⁶

D) (actual yield/theoretical yield)×10³

Q: Which of the following contains maximum number of atoms? (Entry test 2015)

A) 6 mol of sulfur (S)

B) 2 mol of S₈

C) 5 mol of SO₂

D) 44.8 dm³ of CO₂ at STP

Q: The number of atoms in 18 g of H₂O are equal to: (Entry test 2015)

A) 6.02×10²³

B) 6.02×10²⁴

C) 1.806×10²⁴

D) 3.052×10²³

Q: Theoretical yield is always: (Entry test 2015)

A) Less than practical yield

B) Greater than actual yield

C) Both are equal

D) None of the above