1 The empirical formula of a compound is CH₂O. Its molecular formula could be: A CH₂O B C₂H₄O₂ C C₃H₆O₃ D All of these
2 What is the trend in reactivity of Group 1 elements? A Reactivity decreases down the group B Reactivity increases down the group C Reactivity remains the same down the group D Reactivity first increases then decreases
4 Which of the following alkali metals is the most reactive? A Lithium B Sodium C Potassium D Rubidium
5 Which property is typical of acids? A They taste sour B They taste bitter C They feel slippery D They turn red litmus blue
6 In the atomic notation ^A_Z X, the superscript A represents: A atomic number B mass number C number of electrons D number of neutrons
7 The instrument used to determine the relative atomic masses of isotopes is called a: A spectrometer B mass spectrometer C calorimeter D chromatograph
8 Instrumental calibration is done to: A Change the instrument's color B Make the instrument heavier C Ensure correct and reliable measurements D Reduce the instrument's cost
9 Repeating a measurement several times and taking the average helps to: A Remove the need for calibration B Reduce the effect of random errors C Guarantee the result is accurate D Make the reading always exact
10 At equilibrium, the concentrations of reactants and products: A Keep changing B Become zero C Remain constant D Become equal
12 What does an irritant hazard sign indicate? A The chemical can cause irritation to skin, eyes or respiratory system B The chemical is safe C The chemical is explosive D The chemical is flammable
13 Which gas is the main cause of the greenhouse effect? A Nitrogen B Oxygen C Carbon dioxide D Argon
14 Which of the following is the correct name for N2O? A Dinitrogen monoxide B Nitrogen oxide C Nitrogen dioxide D Dinitrogen trioxide
15 The relative atomic mass of an element is expressed relative to which standard? A Carbon-12 B Oxygen-16 C Hydrogen-1 D Chlorine-35
16 Which of the following shows the Tyndall effect? A Salt solution B Sugar solution C Colloidal solution D Pure water
17 Why is it important to calibrate a thermometer before use? A To make it look new B To ensure accurate readings C To change its scale D To increase its range
18 According to Moseley, the modern periodic table is based on which property of elements? A Atomic mass B Atomic number C Density D Valency
20 Neutralisation is the reaction between: A An acid and a base B Two acids C Two bases D An acid and a metal
21 Which of the following is a physical change? A Burning of paper B Rusting of iron C Melting of ice D Digestion of food
22 The discovery of proton is attributed to: A J.J. Thomson B E. Goldstein C James Chadwick D Rutherford
23 Which separation technique is used to separate a mixture of salt and water? A Filtration B Distillation C Evaporation D Chromatography
25 Hydrogen bonding occurs when hydrogen is covalently bonded to: A A highly electronegative atom such as O, N, or F B A metal atom C Another hydrogen atom D A noble gas atom