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 22 of 45
- A. 89.6.
- B. 98.4.
- C. 189.6.
- D. 169.5
Explanation: The correct option is AEquation for the above reaction: CH4 + 2O2 → CO2 + 2H2Omolecular mass of CH4 = 16mass of CH4 given = 32 gno of…
Correct answer: 89.6.- A. 1.3244 x 10^22
- B. 6.02 x 10^20
- C. 6.622 x 10^21
- D. 7.224 x 10^21
Explanation: Ratio of Sucrose : Water in dehydration reaction is = 1 : 11molecular mass of sucrose C12H22O11: (12 x 12) + (1 x 22) + (16 x 11) =…
Correct answer: 1.3244 x 10^22- A. 19 x 10^9
- B. 19 x 10^10
- C. I x 1014
- D. 2 x 10^11
Explanation: Option C is correct. Avagadro number(NA) = 6.02 x 1023 rate = 6.02 x 109 rupees per second time to spend NA rupees = 6.02 x 1023 / 6.02 x…
Correct answer: I x 1014- A. One mole of hydrogen weighs less than one mole of glucose.
- B. Two moles of hydrogen and one mole of helium weigh the same.
- C. 0.1 mole of oxygen weighs more than one mole of hydrogen.
- D. One mole of nitrogen and half a mole of oxygen weigh the same.
Explanation: One mole of nitrogen (N2) has a molar mass of 28.01 g/mol, while half a mole of oxygen (O2) has a molar mass of 15.01 g/mol.
Correct answer: One mole of nitrogen and half a mole of oxygen weigh the same.- A. 2 moles of C atoms, 4 moles of H atoms, 2 moles of O atoms
- B. 1 mole of C atoms, 2 moles of H atoms, 1 mole of O atoms
- C. 2 moles of C atoms, 3 moles of H atoms, 2 moles of O atoms
- D. 2 moles each of C, H and O
Explanation: The molecular formula of acetic acid is CH3COOH. This means that there are 2 carbon atoms, 4 hydrogen atoms, and 2 oxygen atoms in one…
Correct answer: 2 moles of C atoms, 4 moles of H atoms, 2 moles of O atoms- A. 2
- B. 4
- C. 7
- D. 8
Explanation: Mass of nitrogen in 194 amu caffeine N= 28.9gN= 28.9 /100N= 28.9/100 x194 ∴ One molecule of caffeine will contain =56 /14 which is equal…
Correct answer: 4- A. 0.2
- B. 0.4
- C. 0.5
- D. 0.9
Explanation: The molecular formula of sulphuric acid is H2SO4. This means that there is 1 atom of sulphur in one molecule of sulphuric acid.
Correct answer: 0.5- A. The percent efficiency of the reaction.
- B. The theoretical yield of the reaction.
- C. The yield of the reaction.
- D. The theoretical yield of the reactants.
Explanation: Theoretical yield is the maximum amount of product that can be produced from a chemical reaction.
Correct answer: The theoretical yield of the reaction.- A. 12 g
- B. 4.4 g
- C. 44 g
- D. 440 g
Explanation: The balanced equation is: C12H22O11 + 12O2 → 12CO2 + 11H2O From the balanced equation, we can see that the molar ratio between lactose…
Correct answer: 44 g- A. 9.0 x 10^24
- B. 0.75 x 10^24
- C. 3.0 x 10^24
- D. 1 x 10^24
Explanation: The formula of AlF3 suggests that there are three fluoride ions (F-) for each aluminum ion (Al3+).
Correct answer: 1 x 10^24- A. Mass of compound/Mass of element x100
- B. Mass of molecule/Mass of compound x100
- C. Mass of element/Mass of compound x1000
- D. Mass of element/Mass of compound x100
Explanation: Option D is correct as the formula used is element over compound multiplied by 100.
Correct answer: Mass of element/Mass of compound x100- A. CH4
- B. C6H6
- C. CHO
- D. CH2O
Explanation: Option D is correct because this is the empirical fomula of glucose and its simple molecular formula would be C6H12O6.
Correct answer: CH2O433. Atomic mass, molecular mass, formula mass or ionic mass of substance expressed in grams is called:
- A. Avogadro's number.
- B. Molar mass.
- C. Molar volume.
- D. Mole.
Explanation: The mole is a standard unit in chemistry used to count particles (atoms, molecules, ions, etc.).Definition: 👉 One mole of any substance…
Correct answer: Mole.- A. 21 times
- B. 22 times
- C. 23 times
- D. 24 times
Explanation: Option C is correct because mass of hydrogen is 1 and mass of sodium is 23, hence its 23 times more heavier than hydrogen.
Correct answer: 23 times- A. 340 gram of sucrose
- B. 344 gram of sucrose
- C. 342 gram of sucrose
- D. 346 gram of sucrose
Explanation: 1 mole of sucrose has a mass of 342.297g. Thus option C is correct option.
Correct answer: 342 gram of sucrose- A. Isotopes
- B. A half proton
- C. A half neutron
- D. A half electron
Explanation: The Half number in relative atomic mass of Chlorine (i.e 35.5) is due to two naturally occurring isotopes (Chlorine-35 and…
Correct answer: Isotopes- A. Atomic metter unit
- B. Atomic mass unified
- C. Atomic mass unit
- D. Atomic mass unity
Explanation: The correct answer is 'Atomic mass unit'. The abbreviation 'amu' stands for 'atomic mass unit', which is a unit of mass used to express…
Correct answer: Atomic mass unit- A. 342 amu.
- B. 343 amu.
- C. 341 amu.
- D. 340 amu.
Explanation: Molecular Mass of sucrose= (No. of Carbon x Atomic mass of carbon) + (No. of Hydrogen x Atomic mass of hydrogen) + (No.
Correct answer: 342 amu.- A. 11
- B. 23
- C. 12
- D. 22
Explanation: The atomic number represents the number of protons in the nucleus, so if atomic number is 11 it means number protons is 11.
Correct answer: 11- A. Uranium.
- B. Cobalt.
- C. Nickel.
- D. Iodine.
Explanation: Isotope of Cobalt is used in treatment of cancer(Rote Learning).
Correct answer: Cobalt.