Which of the following compounds is an example of an electrovalent bond?
- A. NaCl (sodium chloride)
- B. CO2 (carbon dioxide)
- C. H2O (water)
- D. CH4 (methane)
A blue litmus paper turns red when dipped into a solution. What does this indicate about the solution?
- A. The solution is basic
- B. The solution is neutral
- C. The solution is acidic
- D. The litmus paper is faulty
When a substance is oxidized, it
- A. Loses electrons
- B. Gains oxygen atoms
- C. Gains electrons
- D. Loses protons (H+ ions)
What is the symbol used to represent an alpha particle?
- A. α
- B. γ
- C. δ
- D. β
Which of the following is a common property of non-metals?
- A. Exist as solids at room temperature
- B. Tend to gain electrons in chemical reactions
- C. High thermal conductivity
- D. Readily form cations in chemical reactions
What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)
- A. 25%
- B. 12%
- C. 75%
- D. 50%
What type of reaction is involved in the formation of alkanols from alkenes?
- A. Elimination reaction
- B. Redox reaction
- C. Substitution reaction
- D. Addition reaction
What is the common name for ethanoic acid?
- A. Acetic acid
- B. Butyric acid
- C. Propionic acid
- D. Formic acid
Which separation technique is used to separate different pigments in a mixture based on their affinity for a stationary phase and a mobile phase?
- A. Chromatography
- B. Filtration
- C. Decantation
- D. Distillation
What is the empirical formula of a compound containing 40.00% carbon, 6.67% hydrogen, and 53.33% oxygen by mass?
- A. C\(_4\)H\(_8\)O\(_4\)
- B. CH\(_2\)O
- C. C\(_2\)H\(_4\)O\(_2\)
- D. C\(_3\)H\(_6\)O\(_3\)
What is the main source of carbon monoxide (CO) in urban areas?
- A. Volcanic eruptions
- B. Vehicle emissions
- C. Forest fires
- D. Industrial processes
Which of the following is a primary constituent of crude oil?
- A. Pentane
- B. Ethanol
- C. Heptane
- D. Methane
Which group does calcium belong to in the periodic table?
- A. Alkaline earth metals
- B. Halogens
- C. Alkali metals
- D. Noble gases
What is the principal ore of iron, from which iron is extracted?
- A. Calcite
- B. Bauxite
- C. Magnetite
- D. Hematite
How many pi (\(\pi\)) bonds are there in an alkene with six carbon atoms?
- A. 1
- B. 6
- C. 5
- D. 3
What is the chemical formula of rust, which is formed on the surface of iron in the presence of oxygen and moisture?
- A. Fe\(_3\)O\(_4\)
- B. FeO
- C. Fe(OH)3
- D. Fe\(_2\)O\(_3\)
What is the molar mass of water (H2O)?
- A. 18 g/mol
- B. 22 g/mol
- C. 16 g/mol
- D. 12 g/mol
Which organic compound is responsible for the characteristic aroma of fruits?
- A. Alkane
- B. Alkyne
- C. Ester
- D. Amine
Which of the following factors does NOT affect the rate of a chemical reaction?
- A. Concentration of reactants
- B. Presence of a catalyst
- C. Molecular weight of products
- D. Temperature
When an acidic solution is diluted, what happens to its pH?
- A. It depends on the specific acid
- B. It decreases
- C. It remains the same
- D. It increases
What is the product of the electrolysis of aqueous sodium chloride (NaCl) using inert electrodes?
- A. Hydrogen gas at the cathode and chlorine gas at the anode
- B. Hydrogen gas at the cathode and oxygen gas at the anode
- C. Sodium metal at the cathode and chlorine gas at the anode
- D. Sodium metal at the cathode and oxygen gas at the anode