1 David is studying an ionic compound, NaCl. He wants to calculate the formula mass. He knows Na=23 and Cl=35.5. What is the formula mass of NaCl? A 58.5 g/mol B 60.5 g/mol C 55.5 g/mol D 50.0 g/mol
4 Nora is learning about the effect of temperature on gas solubility. She opens a cold soda can and it is more fizzy than a warm one. What is the relationship between gas solubility and temperature? A Gas solubility increases with temperature B Gas solubility decreases with temperature C Gas solubility is not affected by temperature D Gas solubility increases then decreases
5 Analytical chemistry is used to: A Prepare compounds B Identify substances C Manufacture plastics D Study stars
6 Which substance is necessary for rusting of iron? A Nitrogen B Carbon dioxide C Water and oxygen D Hydrogen
7 Which graph shows activation energy? A Energy vs time B Energy vs reaction progress C Temperature vs time D Pressure vs volume
9 Hina is studying activation energy. She knows that activation energy is the minimum energy required for a reaction to occur. How does a catalyst affect the activation energy? A Increases activation energy B Decreases activation energy C No effect on activation energy D Increases reaction temperature
10 Paula is studying inorganic chemistry applications. She learns that inorganic compounds are used in many products. Which of the following is an example of an inorganic compound used in daily life? A Glucose in food B Table salt C Ethanol in beverages D Acetic acid in vinegar
11 Waseem is studying the properties of matter. He observes that a solid has a fixed shape and volume. What is the arrangement of particles in a solid? A Particles are far apart and move freely B Particles are close but move around each other C Particles are tightly packed in a fixed arrangement and vibrate D Particles are ionized and move freely
12 Fatima is a pharmacist. She uses chemistry to formulate medicines. Which branch of chemistry is most relevant to her work? A Inorganic chemistry B Medicinal chemistry and biochemistry C Geochemistry D Nuclear chemistry
13 Which elements are good conductors of electricity? A Non-metals B Metalloids C Metals D Noble gases
14 Bongani is studying the postulates of Rutherford's atomic model. He learns that Rutherford proposed that the nucleus is positively charged. What did he conclude about the size of the nucleus? A The nucleus is very large compared to the atom B The nucleus is very small and dense compared to the atom C The nucleus is the same size as the atom D The nucleus does not exist
16 Diana is learning about electroplating. She understands that electroplating can be used to coat a metal with a thin layer of another metal. Which of the following is a reason for electroplating? A To increase the metal's reactivity B To improve appearance and prevent corrosion C To make the metal cheaper D To decrease the metal's conductivity
17 Chemical bonding helps to explain: A Weather changes B Physical and chemical properties C Biological growth D Gravity
18 George is studying oxidation states of monoatomic ions. He knows that a monoatomic ion's oxidation state is its charge. What is the oxidation state of Ca2+? A +1 B +2 C -2 D 0
19 Covalent compounds usually have: A High melting points B Low melting points C No melting point D Very high conductivity
20 Ahmed is studying a chemical reaction in a closed flask. He notices that the flask becomes warm to the touch. He knows that energy is being released to the surroundings. What type of reaction is this? A Exothermic reaction B Endothermic reaction C Thermochemical reaction D Catalytic reaction
21 George is comparing atomic sizes of elements. He knows that as we move down a group, the atomic size increases. What is the reason for this trend? A Decrease in number of electron shells B Increase in number of electron shells and shielding effect C Increase in nuclear charge D Decrease in shielding effect
22 Nadia is studying the formula of ionic compounds. She knows that the formula must be neutral. What is the formula of the ionic compound formed between magnesium (Mg2+) and chloride (Cl-)? A MgCl B MgCl2 C Mg2Cl D MgCl3
24 How many particles are present in half mole of a substance? A 3.01 × 10^23 B 6.02 × 10^23 C 1.20 × 10^23 D 12.04 × 10^23
25 The periodic table is arranged in order of increasing: A Atomic mass B Atomic number C Density D Valency
26 Uma is calculating the gram atomic mass of sodium. She knows that the atomic mass of Na is 23 amu. What is the gram atomic mass of sodium? A 23 g B 46 g C 11.5 g D 6.022 × 10^23 g
28 Amina has a glass of orange juice with pulp. The pulp particles are visible and will eventually settle at the bottom if left undisturbed. This is an example of: A Solution B Colloid C Suspension D Element
29 Waleed is learning about symbols for atoms and ions. He knows that the symbol for a sodium ion is Na+. What does the '+' sign indicate? A The atom has gained one electron B The atom has lost one electron C The atom has gained one proton D The atom has lost one proton
30 Heat change measured at constant pressure is: A Internal energy B Enthalpy change C Entropy D Activation energy