1 Diagram 1 shows the way to store a solution. Which of the following properties is the reason why the solution is stored in a dark bottle? flag bookmark A Easily decomposed B Easily explodes C Volatile and flammable D Easily reacts with moisture in the air T4 Chapter 1.3 Usage, Management and Handling of Apparatus and Materials Hydrogen peroxide decomposes easily into water and oxygen when exposed to light. A dark bottle blocks light and slows down the decomposition.
2 Which substance is an element? flag bookmark A Water B Carbon C Ammonia D Air T4 Chapter 2.1 Basic Concepts of Matter Carbon is made of only one type of atom, so it is an element. Water and ammonia are compounds, and air is a mixture.
3 Diagram 2 shows the arrangement of particles for a change of state of matter. Which of the following substances will undergo process X? flag bookmark A Naphthalene B Table salt C Glucose D Vinegar T4 Chapter 2.1 Basic Concepts of Matter Process X changes a solid directly into a gas (sublimation). Naphthalene sublimes when heated. Table salt and glucose melt, and vinegar is a liquid.
4 What is the unit for the Avogadro constant? flag bookmark A mol B mol⁻¹ C g mol⁻¹ D dm³ mol⁻¹ T4 Chapter 3.2 Mole Concept The Avogadro constant is the number of particles in one mole, 6.02 × 10²³ per mole, so its unit is mol⁻¹.
5 Which of the following cations is matched correctly with its charge? flag bookmark A Zinc ion: +1 B Potassium ion: +2 C Aluminium ion: +1 D Magnesium ion: +2 T4 Chapter 3.3 Chemical Formula Magnesium is in Group 2 and loses two electrons to form Mg²⁺, a +2 ion. Zinc ions are Zn²⁺, potassium ions K⁺ and aluminium ions Al³⁺.
6 Which of the following elements is located in Group 17 of the Periodic Table of Elements? flag bookmark A Magnesium B Helium C Lithium D Chlorine T4 Chapter 4.2 The Arrangement in the Periodic Table of Elements Chlorine is a halogen and is placed in Group 17. Magnesium is in Group 2, helium in Group 18 and lithium in Group 1.
7 What is the meaning of a covalent bond? flag bookmark A A bond formed when metal atoms contribute electrons to each other to achieve a stable electron arrangement B A bond formed when non-metal atoms share electrons to achieve a stable electron arrangement C A bond formed when a metal atom transfers an electron to a non-metal atom D A bond formed by weak van der Waals forces between non-metal atoms T4 Chapter 5.3 Covalent Bond A covalent bond forms when non-metal atoms share pairs of electrons so that each atom achieves a stable (duplet or octet) electron arrangement.
8 Table 1 shows the pH values of four alkaline solutions. | Solution | pH value | |---|---| | W | 8.0 | | X | 9.0 | | Y | 11.0 | | Z | 13.0 | Which solution has the highest concentration of hydroxide ions? flag bookmark A W B X C Y D Z T4 Chapter 6.2 pH Value The higher the pH of an alkali, the higher the concentration of hydroxide ions. Z has the highest pH (13.0), so it has the highest OH⁻ concentration.
9 In an experiment, damp blue litmus paper turns red when inserted into a test tube containing gas X. Which of the following statements is correct about X? flag bookmark A Dissolves in water and ionises to form hydrogen ions B Dissolves in water to produce a high concentration of hydroxide ions C Produced from the reaction between an acid and an alkali T4 Chapter 6.1 The Role of Water in Showing Acidic and Alkaline Properties Gas X turns damp blue litmus red, so it is acidic. An acidic gas dissolves in water and ionises to form hydrogen ions, H⁺.
10 Which of the following is the correct method to calculate the rate of reaction at the third second? flag bookmark A B C D T4 Chapter 7.1 Determining Rate of Reaction The rate at a given instant is the gradient of the tangent to the curve at that time. Graph C draws a tangent at 3 s and uses its gradient.