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 17 of 45
- A. 0.5
- B. 0.3
- C. 0.2
- D. 0.1
Explanation: 22.4 litres of CO2 has 44 grams weight. It is equal to 1 mole. In 11.2 litres of CO2 , it weighs only 22 grams.
Correct answer: 0.5- A. Isotopes
- B. Isobars
- C. Isotones
- D. Isomers
Explanation: Isotopes: Atoms of the same element with the same number of atomic numbers but a different mass number.Isotones: Species or atoms having…
Correct answer: Isobars- A. 2.24 dm3
- B. 112 cm3
- C. 22.4 dm3
- D. 1.12 dm3
Explanation: At STP (Standard Temperature and Pressure), 1 mole of any gas occupies 22.4 dm3. The molar mass of CO2 is 44g/mol.
Correct answer: 2.24 dm3- A. 32 g
- B. 71 g
- C. 35.5 g
- D. 46 g
Explanation: Relative atomic mass of Cl= 35.5 amuThe relative molecular mass of Cl2 gas= 71 amuMolecular mass expressed in grams is called mole.
Correct answer: 71 g- A. It is a counting unit
- B. It represents the gram atomic or gram molecular mass of a substance
- C. It contains 6.022 x 10^23 particles (Avogadro's number)
- D. It contains different numbers of particles for different substances
Explanation: Option d is correct because moles represent a quantity of substance, and this quantity will differ for different substances due to their…
Correct answer: It contains different numbers of particles for different substances- A. A limiting reactant is consumed at the end of a reaction.
- B. Theoretical yield is always lower than actual 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: The correct answer is Option B. Theoretical yield is the calculated maximum amount of product that can be produced in a chemical reaction…
Correct answer: Theoretical yield is always lower than actual yield.- A. 30
- B. 35
- C. 38
- D. 36
Explanation: Number of neutrons = Mass number - atomic number Number of neutrons = 66 - 30 Number of neutrons = 36
Correct answer: 36- A. 120ml
- B. 20ml
- C. 40ml
- D. 60ml
Explanation: To determine the volume of 0.1 M Ca(OH)2 needed to neutralize the same volume of the given H3PO4 solution, we can use the concept of…
Correct answer: 60ml- A. 200/3 g
- B. 24 g
- C. 34 g
- D. 48 g
Explanation: The balanced chemical equation is 3Mg+2NH3→Mg3N2+3H2 48 g of magnesium will react with (48×2×17)/(24×3)=22.67 g of ammonia.However, 34 g…
Correct answer: 200/3 g- A. 1 mg of C4H10
- B. 1 mg of N2
- C. 1 mg of Na
- D. 1 mg of H2O
Explanation: The correct answer is 1 mg of C4H10 because it has the highest total number of atoms (14 atoms per molecule).
Correct answer: 1 mg of C4H10- A. 4
- B. 6
- C. 2
- D. 3
Explanation: The correct answer is 4, as the molecular formula for caffeine is C8H10N4O2. This means there are 4 nitrogen atoms in each molecule.
Correct answer: 4- A. 100
- B. 106
- C. 103
- D. 104
Explanation: Following is the solution to this question:
Correct answer: 104333. What is the empirical formula of a compound composed of O and Mn in equal weight ratio? [Mn = 55]
- A. MnO
- B. MnO2
- C. Mn2O3
- D. Mn2O7
Explanation: The numerical solution is given below:Mn2O7 Mass of Mn = 55 x 2 = 110Mass of O= 16 x 7 = 112
Correct answer: Mn2O7- A. 10
- B. 20
- C. 15
- D. 25
Explanation: Normality (N) is given by the formula: N = (Number of moles of solute) / (Volume of solution in liters) Let's find the number of moles of…
Correct answer: 20- A. 0.018
- B. 0.02
- C. 0.04
- D. 0.3
Explanation: The molarity of KMnO4 solution can be calculated using the formula: Molarity (M) = (Volume of KMnO4 solution in liters) / (Number of moles…
Correct answer: 0.018- A. 32 g
- B. 41.2 g
- C. 80 g
- D. 156 g
Explanation: Following is the solution to this question:To find the molecular mass of the alcohol, we can use the formula:Molecular mass = (Mass of…
Correct answer: 80 g- A. One mole of H2
- B. One mole of O2
- C. Half mole of H2
- D. Half mole of O2
Explanation: When magnesium (Mg) reacts with an acid, it typically displaces hydrogen, forming hydrogen gas (H2).
Correct answer: Half mole of H2- A. 16
- B. 12
- C. 11
- D. 8
Explanation: When hydrocarbon reacts with oxygen it forms carbon dioxide and water.C5 H1 2+O2 →CO2 +H2 OStart by using the 5 carbons in the hydrocarbon…
Correct answer: 8- A. 0.1 mol and 0.3 mol
- B. 0.05 mol and 0.15 mol
- C. 0.02 mol and 0.06 mol
- D. 0.1 mol and 0.15 mol
Explanation: To find the correct amounts of KIO3 consumed and ICl formed, first, the balanced chemical equation must be established.
Correct answer: 0.05 mol and 0.15 mol- A. 4.8 x 10^22
- B. 4.8 x 10^24
- C. 9.6 x 10^24
- D. 9.6 x 10^22
Explanation: Step 1: Dissociation of the compoundK₄[Fe(CN)₆] is an ionic compound and dissociates in water as:K4 [Fe(CN)6 ]→4K++[Fe(CN)6 ]4− So, 1 mole…
Correct answer: 4.8 x 10^24