Advanced level 2026 BAEBOC chemistry 1

This document contains 12 multiple-choice questions related to Chemistry. Below is the extracted data from the provided image:

Questions 1-12

1. Which of the following represents the correct shape and bond angle of ethene ($C_2H_4$) respectively?

   • A. Tetrahedral and $109.5^\circ$

   • B. Linear and $180^\circ$

   • C. Planar and $120^\circ$

   • D. V-shape(bent) and $104.5^\circ$

2. Select from the list below, the graph that corresponds to the first order reaction when $Ln [A]$ is plotted against time. $A$ is a reactant.

   • Graph A: Linear positive slope.

   • Graph B: Linear negative slope starting from y-intercept.

   • Graph C: Exponentially increasing curve.

   • Graph D: Exponentially decreasing curve.

3. Study the experimental lattice energy values of the ionic compounds below and select the correct order of increasing stability, beginning with the least stable.

   | Compound | MgO | NaCl | CaO | NaF |

   | :— | :— | :— | :— | :— |

   | L.E/$\text{KJmol}^{-1}$ | -3933 | -776 | -3401 | -915 |

   • A. MgO, CaO, NaF and NaCl.

   • B. NaCl, NaF, MgO and CaO

   • C. NaF, CaO, NaCl and MgO

   • D. NaCl, NaF, CaO and MgO

4. Determine the volume of water needed to dilute $200\text{cm}^3$ of $0.25\text{M}$ NaOH solution to $0.2\text{M}$.

   • A. $50\text{cm}^3$

   • B. $100\text{cm}^3$

   • C. $250\text{cm}^3$

   • D. $500\text{cm}^3$

5. Select from the list below, the theory that best describes what just happens before products are formed during a chemical reaction.

   • A. Collision theory

   • B. Kinetic theory

   • C. Transition state theory

   • D. Le Chatelier’s principle

6. The equilibrium constant, Kc for the reaction: $N_{2(g)} + 3H_{2(g)} \rightleftharpoons 2NH_{3(g)}$ can be affected by:

   • A. Change in pressure

   • B. Change in temperature

   • C. Using a catalyst

   • D. Change in concentration of $NH_{3(g)}$

7. The pure vapor pressures of methanol and ethanol are $28\text{mmHg}$ and $22\text{mmHg}$ respectively, assuming that the mole fraction of ethanol is $0.46$. Determine the partial vapour pressure of methanol in the mixture.

   • A. $12.88\text{mmHg}$

   • B. $10.12\text{mmHg}$

   • C. $50\text{mmHg}$

   • D. $15.12\text{mmHg}$

8. Which of the following is responsible for the x-ray diffraction in crystal lattice?

   • A. Electrons

   • B. Atoms

   • C. Protons

   • D. Nucleus

9. A Lewis acid is defined as:

   • A. A proton donor

   • B. A proton acceptor

   • C. An electron pair donor

   • D. An electron pair acceptor

10. How many phases and components are found in the equilibrium reaction system below:

    $CaCO_{3(s)} \rightleftharpoons CaO_{(s)} + CO_{2(g)}$

    • A. 3 phases and 3 components

    • B. 2 phases and 2 components

    • C. 2 phases and 3 components

    • D. 3 phases and 2 components

11. Calculate the pH of $0.025\text{M}$ $H_2SO_4$ according to the equation below:

    $H_2SO_{4(aq)} \rightarrow 2H^+_{(aq)} + SO^{2-}_{4(aq)}$

    • A. 1.60

    • B. 2.30

    • C. 1.30

    • D. 2.60

12. Consider the equation; $H_{2(g)} \rightarrow 2H_{(g)}$; $\Delta H$. Name the energy change represented by $\Delta H$:

    • A. Enthalpy change of atomization

    • B. Bond dissociation energy

    • C. Enthalpy change of ionization

    • D. Enthalpy change of Neutralization

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