Free Fundamental Concepts of Chemistry MCQs with Answers
894 Fundamental Concepts of Chemistry MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Mole calculations connect mass, number of particles and Avogadro's number, while balanced equations provide the mole ratios used in stoichiometry. Questions cover limiting and excess reactants, theoretical yield and percentage yield, including identifying which reactant is consumed first and comparing the actual product with the maximum possible product.
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Read the Fundamental Concepts of Chemistry notesFree MDCAT chapter notes with key terms894 questions · page 19 of 45
- A. Mass-mass relationship
- B. Mass-volume relationship
- C. Mass-mole relationship
- D. Mole-volume relationship
Explanation: Option B is correct because it refers to the principle that if you know the mass of one substance involved in a chemical reaction, you can…
Correct answer: Mass-volume relationship- A. Cr
- B. Ca
- C. Mg
- D. Mn
Explanation: M+S-4 MSStoichlometrically, S:MI mole: I mole0.09 mole: 0.09 moleand 0.09 mole of M = 3.6gI mole of M =3640g or Ca.0.09
Correct answer: Ca- A. Is consumed earlier
- B. Controls the reaction
- C. Gives least moles of product
- D. All of these
Explanation: A limiting reactant is the one which controls the reaction.It is consumed earlier in the reaction and produces the least number of moles…
Correct answer: All of these- A. 428g
- B. 448g
- C. 438g
- D. 458g
Explanation: Mg + 2HCl => MgCl2 + H2mol. 1mol. 2:1Mr of HCl= 1 + 35.5 = 36.5Mr of H2= 2x1 = 236.5 x 2g HCl required to produce 2g of H2,thus in order…
Correct answer: 438g- A. One mole
- B. Gram atomic mass
- C. Atomic number
- D. Relative atomic mass
Explanation: The mass of an atom of an element compared with the mass of one atom of carbon-12 (C-12) is called the relative atomic mass because it…
Correct answer: Relative atomic mass- A. 0.25
- B. 1.0
- C. 0.50
- D. 1.50
Explanation: 16g grams of oxygen(O) in moles = Mass/Mr = 16/16 = 1 mole 1 mole of NO2 contains 2 moles of O (as in every 1 molecule of NO2 there are…
Correct answer: 0.50- A. 1.008x1.661 x 10^-23 kg
- B. 1.008x1.661 x 10^-27kg
- C. 1.00 kg
- D. 1.661 x 10^-27kg
Explanation: 1 amu = 1.661x10-27 kg. So, 1.008 amu = 1.661x10-27 x 1.008 kg
Correct answer: 1.008x1.661 x 10^-27kg- A. 6.02 x 10^22
- B. 6.0 x 10^23
- C. 3.6 x 10^23
- D. 3.6 x 10^24
Explanation: 1.2g of carbon present; Molecular mass of carbon = 12Moles = Mass/Mr = 1.2/12 = 0.1 molNo.
Correct answer: 6.02 x 10^22- A. 1 mole
- B. 2 moles
- C. 0.5 mole
- D. 0.25 moles
Explanation: To find the number of moles of magnesium (Mg) required, consider the stoichiometry of the reaction: Mg + 2HCl → MgCl2 + H2.
Correct answer: 0.5 mole- A. 35.5g
- B. 71 g
- C. 142 g
- D. 71.5 g
Explanation: H2 + Cl2-> 2HCl Moles of H2 = mass/mr = 4/2 = 2 The molar ratio of H2 and Cl2 is H2 : Cl2 = 1 : 1 So, moles of Cl2 = 2 moles Mr of Cl2=…
Correct answer: 142 g- A. Expected yield
- B. Actual yield
- C. Yield from balanced equation
- D. Theoretical yield
Explanation: The most doubtful yield is the actual yield. This is because the actual yield is the amount of product that is actually produced in a…
Correct answer: Actual yield- A. 100°C, 1 atm
- B. 298 K, 1 atm
- C. 273 K, 760 mm Hg
- D. 0°C, 760 cm Hg
Explanation: Standard conditions for temperature and pressure (STP) in chemistry are defined as 273 K (0°C) and 1 atm pressure, which is equivalent to…
Correct answer: 273 K, 760 mm Hg- A. 6.02 x 10^22
- B. 6.02 x 10^23
- C. 3.6 x 1 022
- D. 3.6 x 1 023
Explanation: The molecular formula of glucose is C6H12O6, which means that there are 6 carbon atoms in every molecule of glucose.
Correct answer: 3.6 x 1 023- A. Five
- B. Four
- C. Six
- D. Three
Explanation: 2H₂ + O₂ → 2H₂OThis equation indicates that 2 moles of hydrogen (H₂) react with 1 mole of oxygen (O₂) to produce 2 moles of water (H₂O).
Correct answer: Four- A. 64 dm3
- B. 24 dm3
- C. 22.4 dm3
- D. 2.24 dm3
Explanation: The molar volume of any ideal gas at Standard Temperature and Pressure (STP) is approximately 22.4 liters per mole (L/mol).
Correct answer: 22.4 dm3- A. 0.4 moles
- B. 0.3 moles
- C. 0.2 moles
- D. None of these
Explanation: No. of moles of Oxygen = 10.6/106 x NA x 3= 0.3 NA or 0.3 moles
Correct answer: 0.3 moles- A. 21 grams
- B. 19 grams
- C. 18 grams
- D. 15 grams
Explanation: Mass of CH4 = 8g Molar mass CH4 = 16g/mol Moles = 8g/16g/mol = 0.5mol CH4 + 2O2 → CO2+ 2H2O Compare the mole ratios.
Correct answer: 18 grams- A. Neon-20
- B. Carbon-13
- C. Nucleon number
- D. Carbon -12
Explanation: Relative atomic mass is the mass of an atom of an element as compared to the mass of an atom of carbon taken as 12.
Correct answer: Carbon -12- A. 32.0g O2
- B. 44.0g CO2
- C. 8.00g H2
- D. 56.0g N2
Explanation: Molar mass of H2 = 2 x 1.01 g/mol = 2.02 g/molMoles of H2 = Mass (g) / Molar mass (g/mol)Moles of H2 =8.00 g / 2.02 g/mol = 4 molNo.
Correct answer: 8.00g H2- A. 12%
- B. 10%
- C. 48%
- D. 40%
Explanation: Calcium (Ca) has a molar mass of 40 g/mol. Carbon (C) has a molar mass of 12 g/mol.
Correct answer: 40%