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 9 of 45
- A. a hypothesis
- B. a fact
- C. a law
- D. an observation
Explanation: This statement reflects the Law of Definite Proportions, which states that a compound always contains the same elements in the same fixed…
Correct answer: a law- A. HF(I)
- B. HCI(I)
- C. HBR(I)
- D. HI(I)
Explanation: The boiling point of a compound is influenced by the strength of intermolecular forces.
Correct answer: HI(I)- A. one calorie
- B. little bit greater than on calorie
- C. little bit less than one calorie
- D. never equal to one calorie
Explanation: The amount of heat required to raise the temperature of 11 grams of water from 30°C to 31°C is approximately one calorie 1.
Correct answer: one calorie- A. XY2
- B. X2Y
- C. X3Y
- D. XY
Explanation: To determine the empirical formula of the compound, we need to calculate the number of moles of each element in the compound.Let's assume…
Correct answer: XY2- A. 2.4 x 10 ^25
- B. 40
- C. 4 x 10 ^24
- D. 6.4 x 10 ^21
Explanation: The number of covalent bonds in 10 moles of carbon tetrachloride (CCl4) can be calculated as follows:One molecule of CCl4 contains four…
Correct answer: 2.4 x 10 ^25- A. 10.234017
- B. 10.2340178
- C. 10.234
- D. 10.23
Explanation: Let's check the subtraction of 0.00055 from 10.2345678:10.2345678−0.0005510.2345678−0.00055Calculating this…
Correct answer: 10.2340178- A. a gas is liberated
- B. colour of the gas is greenish yellow
- C. oxide of the gas is strongly acidic
- D. the gas is chlorine
Explanation: "The gas is chlorine" - This is a conclusion. It identifies the gas based on its properties and behavior.
Correct answer: the gas is chlorine- A. energy obtained from uranium will be too much greater than that of hydrogen
- B. energy obtained from hydrogen will be a little bit less than that of uranium
- C. energy obtained from hydrogen and uranium will always be exactly equal
- D. diamond
Explanation: The equation E=m c2 represents Einstein's mass-energy equivalence formula, where E is the energy, m is the mass, and c is the speed of…
Correct answer: energy obtained from uranium will be too much greater than that of hydrogen- A. 0.92
- B. 0.920
- C. 0.9200
- D. 1.087
Explanation: The density (D) is calculated using the formula:D= massvolumeIn this case, the mass is 46.0 g and the volume is 50.00 mL.D=46.0 g/50.00…
Correct answer: 0.920- A. 6.02 x 10^22
- B. 6.02 x 10^23
- C. 3.61 x 10^23
- D. 6 x 10^23
Explanation: As one ozone molecule contains 3 oxygen atoms 1 Mole of Ozone = 3 × 6.022 × 10 ^ 23 Oxygen Atoms0.2 Moles Of Ozone = 3 × 6.022 × 10 ^23 ×…
Correct answer: 3.61 x 10^23- A. CaSO4
- B. CaSO3. 1⁄2 H2O
- C. CaSO4.H2O
- D. CaSO4.2H2O
Explanation: The number of water molecules associated with the hydrated salt can be determined by the ratio of moles of water lost to moles of the…
Correct answer: CaSO3. 1⁄2 H2O- A. 0.1
- B. 0.01
- C. 0.20
- D. 0.05
Explanation: The balanced chemical equation for the reaction is:ZrCl4 + 2Mg → Zr+ 2MgCl2According to the balanced equation, 1 mole of Zirconium (Zr) is…
Correct answer: 0.1- A. 4.32%
- B. 8.23%
- C. 12.4%
- D. 17.3%
Explanation: The mass percentage of nitrogen in nicotine can be calculated as follows:Calculate the molar mass of nicotine:Molar mass of…
Correct answer: 17.3%- A. NaCIO2
- B. NaCIO3
- C. NaCIO
- D. NaCIO4
Explanation: To determine the empirical formula of the ionic compound, we need to calculate the number of moles of each element in the compound.Let's…
Correct answer: NaCIO4- A. 1.2g
- B. 1.4g
- C. 1.6g
- D. 1.8g
Explanation: We are given a 0.3 molal solution of urea in 100g of water. Molality (m) is defined as the number of moles of solute (urea) per kilogram…
Correct answer: 1.8g- A. 0.8%
- B. 80%
- C. 8.0%
- D. 20%
Explanation: Boron has two main isotopes: Boron-10 (⁵B¹⁰) and Boron-11 (⁵B¹¹). The relative atomic mass of boron, which is the weighted average of the…
Correct answer: 20%- A. Ground state
- B. Ionized state
- C. Metastable state
- D. Ordinary excited state
Explanation: The excited state that persists for an unusually longer period of time is called a metastable state.
Correct answer: Metastable state- A. 80%
- B. 30%
- C. 40%
- D. 20%
Explanation: Molecular formula of calcium carbonate: CaCO₃Atomic masses:Calcium (Ca): 40.078 amuCarbon (C): 12.011 amuOxygen (O): 15.999 amuCalculate…
Correct answer: 40%- A. SO
- B. 2O3
- C. SO3
- D. SO2
Explanation: Analyze the mass percentages: The compound has 50% sulfur (S) and 50% oxygen (O).Convert percentages to moles:Moles of S = (50 g S / 32.07…
Correct answer: SO2- A. 81
- B. 80
- C. 79.5
- D. 79
Explanation: To calculate the average atomic mass of bromine, we consider the weighted average of the individual isotope masses and their relative…
Correct answer: 80