1 Which of the following substances consists of ions? flag bookmark A Argon B Copper C Carbon dioxide D Sodium chloride T4 Chapter 2.1 Basic Concepts of Matter Sodium chloride is an ionic compound made of $\text{Na}^+$ and $\text{Cl}^-$ ions. Argon consists of atoms, copper of metal atoms, and carbon dioxide of molecules.
2 Diagram 1 shows the standard representation of an aluminium atom. $^{27}_{13}\text{Al}$ What is the number of valence electrons of the atom? flag bookmark A 3 B 7 C 13 D 14 T4 Chapter 2.3 Atomic Structure Proton number 13 gives 13 electrons with the arrangement 2.8.3, so the atom has 3 valence electrons.
3 Diagram 2 shows the arrangement of particles for a change of state of matter. Which of the following is process W? flag bookmark A Sublimation B Condensation C Evaporation D Melting T4 Chapter 2.1 Basic Concepts of Matter The particles change from closely packed in an orderly arrangement (solid) to closely packed but disorderly (liquid). Solid to liquid is melting.
4 The following chemical equation represents a reaction. $$\text{NaHCO}_3 + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2$$ What are the reactants in this equation? flag bookmark A Sodium hydrogen carbonate and hydrochloric acid B Sodium hydrogen carbonate and sodium chloride C Sodium chloride, water and carbon dioxide D Sodium carbonate and hydrochloric acid T4 Chapter 3.4 Chemical Equation Reactants are written on the left of the arrow: $\text{NaHCO}_3$ (sodium hydrogen carbonate) and HCl (hydrochloric acid).
5 Table 1 shows elements with their respective proton numbers. | Element | Proton number | |---|---| | W | 9 | | X | 11 | | Y | 19 | | Z | 20 | Which pair of elements has the same chemical properties? flag bookmark A W and X B W and Y C X and Y D X and Z T4 Chapter 4.2 The Arrangement in the Periodic Table of Elements X (2.8.1) and Y (2.8.8.1) both have 1 valence electron, so they are in Group 1 and have the same chemical properties.
6 Diagram 3 shows four elements in the Periodic Table of Elements. Which of the following elements can be used as a catalyst in a chemical reaction? flag bookmark A P B Q C R D S T4 Chapter 4.7 Transition Elements Q is in the middle block of the Periodic Table, so it is a transition element. Transition elements and their compounds are used as catalysts.
7 Diagram 4 shows a student applying solution X to his wound to kill bacteria. Which of the following Group 17 elements is the most suitable to be used to make solution X? flag bookmark A Fluorine B Chlorine C Bromine D Iodine T4 Chapter 4.5 Elements in Group 17 Iodine dissolved in alcohol (tincture of iodine) is used as an antiseptic to kill bacteria on wounds. The other halogens are too reactive or toxic to put on skin.
8 Diagram 5 shows a type of bond. What is the name of the bond? flag bookmark A Ionic bond B Covalent bond C Metallic bond D Dative bond T4 Chapter 5.6 Metallic Bond Valence electrons are released to form a sea of delocalised electrons around positively charged metal ions. The attraction between them is a metallic bond.
9 Which of the following statements about the formation of a dative bond is correct? flag bookmark A Ammonia when dissolved in water cannot form a dative bond B A pair of electrons shared are from one atom only C It is also known as a metallic bond D It is a type of ionic bond T4 Chapter 5.5 Dative Bond A dative (coordinate) bond is a covalent bond in which both shared electrons come from the same atom, for example when $\text{NH}_3$ donates its lone pair to $\text{H}^+$.
10 Which of the following is a soluble salt? flag bookmark A Silver chloride B Lead(II) chloride C Sodium sulphate D Barium sulphate T4 Chapter 6.8 Salts, Crystals and Their Uses in Daily Life All sodium salts are soluble in water. Silver chloride and barium sulphate are insoluble, and lead(II) chloride is insoluble in cold water.