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 38 of 45
- A. CH₂O
- B. C₂H₄O₂
- C. C₆H₁₂O₆
- D. C₃H₆O₃
Explanation: A molecule of glucose contains 6 carbon atoms, 12 hydrogen atoms, and 6 oxygen atoms.
Correct answer: C₆H₁₂O₆- A. Ionic bond
- B. Hydrogen bond
- C. Covalent bond
- D. None of these options are correct
Explanation: Covalent bonding has a characteristic feature which involves the sharing of electrons between two non-metal atoms.
Correct answer: Covalent bond743. Isotopes are?
- A. Chemically similar
- B. Physically dissimilar
- C. Chemically dissimilar
- D. Both Options A and B are correct
Explanation: As the atomic number of different isotopes of an element is the same, they have the same electronic configuration hence they will show the…
Correct answer: Both Options A and B are correct- A. Chlorine molecules in 35.5g of chlorine gas
- B. Electrons in 1g of Hydrogen gas
- C. Hydrogen ions in 1 dm3 of 1 moldm-3 aqueous sulphuric acid
- D. Oxygen atoms in 22.4 dm3 of oxygen gas at STP
Explanation: 1g Hydrogen is equal to one-mole hydrogen atom and each atom of hydrogen contains one electron so there will be one-mole electron.
Correct answer: Electrons in 1g of Hydrogen gas- A. 0.08
- B. 0.80
- C. 80
- D. 1280
Explanation: Mol of oxygen = given particles/ avagadros number = 1.5 x 1022 /6.02 x 1023 = 0.025 molmass= mole x molar mass of O20.025 x 32= 0.80g
Correct answer: 0.80- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Option B is correct.we know that No. of electron=n*NA =1.0*10-6*6.02*1023
Correct answer: Option B- A. 2x6.022 x 10^23 atoms
- B. 2 x 10^23 atoms
- C. 35.5 x 6.022 x 10^23 atoms
- D. 2x6.02 x 10^22 atoms
Explanation: Number of atoms = n X NANo. of CI atoms = 2 x 6.02x1023
Correct answer: 2x6.022 x 10^23 atoms- A. 1.008 mg
- B. 0.55 mg
- C. 1.09 mg
- D. 0.275 mg
Explanation: The mass of one mole of electrons is approximately 5.48579909070 × 10-4 grams.
Correct answer: 1.09 mg- A. 1.6 x 10^21
- B. 9.0 x 10^22
- C. 3.6 x 10^23
- D. 6.02 x 10^23
Explanation: To determine the total number of atoms in 0.125 moles of S8 molecules, we use the formula:Number of Atoms = Moles × Avogadro's Number ×…
Correct answer: 6.02 x 10^23- A. 6.02 x 10^23 atoms of C
- B. 6.02 x 10^23 atoms of O
- C. 8.1 x 10^23 atoms of CO2
- D. 5.0 g atoms of CO2
Explanation: The correct option is A. 1 mole of any substance conatins Avagadro (NA = 6.02 x 1023) number of atoms.
Correct answer: 6.02 x 10^23 atoms of C- A. 1 mole means 6.023 x 10^23 particles.
- B. Molar mass is mass of 1 molecule.
- C. Molar mass is the mass of 1 mole of substance.
- D. Molar mass is molecular mass expressed in grams.
Explanation: Option B is incorrect. Molar mass is the mass of 1 mole of a substance and not the mass of molecule itself.
Correct answer: Molar mass is mass of 1 molecule.- A. 2.5 g
- B. 3 g
- C. 4 g
- D. 1 g
Explanation: We first have to find the moles of CO2. Since the volume of CO2 is given at STP, we can use the molar volume of a gas at STP, which is…
Correct answer: 4 g- A. 1.66 x 10^-27 kg
- B. 2.45 x 10^-31 kg
- C. 2.77 x 10^34 kg
- D. 9.34 x 10^-25 kg
Explanation: Fact, learn it (it is 1/12th the mass of Carbon-12).
Correct answer: 1.66 x 10^-27 kg- A. CO2
- B. HO
- C. H2
- D. H2O
Explanation: The empirical formula for water is H2O, which indicates that each molecule of water consists of 2 hydrogen atoms bonded to 1 oxygen atom.
Correct answer: H2O- A. 10NA
- B. 5.5NA
- C. 5
- D. 5NA
Explanation: Each Na+ has 10 electrons so in half mole of Na+ there will be 6.02x10^23 /2 ions.If we take 6.02x10^23 as NA 1 Na+ => 10 electrons NA/2…
Correct answer: 5NA- A. A limiting reagent is consumed at the end of the reaction
- B. Actual yield is always greater than theoretical yield
- C. Stoichiometric calculations can only be done if no side reaction happens
- D. The empirical formula and molecular formula of some compounds are the same
Explanation: Actual yield is less than theoretical yield due to the following reasons i) side reactions may produce by-productsii) some reactions are…
Correct answer: Actual yield is always greater than theoretical yield- A. Atomic meter unit.
- B. Atomic mass unified.
- C. Atomic mass unit.
- D. Atomic mass unity.
Explanation: The correct answer is 'Atomic mass unit'. The abbreviation 'amu' is commonly used in chemistry to denote a unit of mass that is precisely…
Correct answer: Atomic mass unit.- A. 342
- B. 343
- C. 341
- D. 340
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- A. 1.66×10-²⁷ kg
- B. 2.45×10-³¹ kg
- C. 2.77 x 10^34 kg
- D. 9.34×10-²⁵ kg
Explanation: The atomic mass unit (AMU or amu) of an element is a measure of its atomic mass.
Correct answer: 1.66×10-²⁷ kg- A. Electronic configuration is the same because atomic number is same.
- B. Isotopes have same atomic number.
- C. Isotopes of an element have different mass number.
- D. Isotopes of an element have different atomic number.
Explanation: The variation of atomic mass in isotopes can influence its physical properties like Density, Melting and boiling point and…
Correct answer: Isotopes of an element have different mass number.