CHEMISTRY MCQS
1. Which of the following is a noble gas?OxygenNitrogenArgonHydrogenC) Argon Argon is a noble gas found in Group 18 of the periodic table.
What is the chemical formula of water?H2OCO2NaCl CH4 A) H2OWater is composed of two hydrogen atoms and one oxygen atom.
Which acid is present in vinegar?Citric acidHydrochloric acidAcetic acidSulphuric acidC) Acetic acidVinegar is a dilute solution of acetic acid in water.
The atomic number of carbon is:268 12: B) 6 Carbon has 6 protons, defining its atomic number.
Which of the following is an alkali metal? CalciumSodium Aluminum Zinc: B) Sodium Sodium is in Group 1, the alkali metals.
Which element is liquid at room temperature? Mercury Iron CopperLeadA) MercuryMercury is the only metal that is liquid at room temperature.
What is the pH of pure water? 15 79C) 7Pure water is neutral with a pH of 7.
Which gas turns limewater milky?OxygenNitrogen Carbon dioxide Hydrogen C) Carbon dioxide Carbon dioxide reacts with limewater to form calcium carbonate, turning it milky.
Which of the following is a mixture?Water Carbon dioxide Air Glucose: C) Air Air is a mixture of various gases.
What is the symbol of Potassium? PoP PtKD) KThe symbol 'K' comes from the Latin name 'Kalium'.
Which bond is strongest? IonicCovalent Metallic Hydrogen B) CovalentCovalent bonds involve the sharing of electron pairs and are generally stronger.
Which element is used in pencils?Lead Graphite Carbon ZincB) GraphitePencils use graphite, a form of carbon.
Which gas is used in balloons?Helium Oxygen Hydrogen NitrogenA) Helium: Helium is safe and lighter than air, ideal for balloons.
What is the main ore of aluminum?BauxiteHematite Galena PyriteA) BauxiteBauxite is the primary source of aluminum.
What is the chemical formula of common salt?Na2CO3 NaCl KCl CaCl2B) NaCl Common salt is sodium chloride (NaCl).
What is the chemical symbol for the element 'Gold'?AgAuFePbB) AuThe chemical symbol for gold is Au, derived from its Latin name, aurum.
What is the pH value of a neutral substance, such as pure water?071410B) 7The pH scale measures how acidic or basic a substance is. A pH of 7 is considered neutral, with values below 7 being acidic and values above 7 being basic (alkaline).
Which of the following is an inert gas?OxygenNitrogen NeonChlorineC) NeonNeon is a noble gas (also known as an inert gas) that belongs to Group 18 of the periodic table and is known for its low reactivity.
What is the common name for the compound sodium chloride (NaCl)?Baking sodaEpsom saltTable saltBleachC) Table saltSodium chloride is the chemical name for the ionic compound commonly known as table salt.
The process of a liquid turning into a gas is called:MeltingFreezingEvaporationCondensationC) EvaporationEvaporation is the process by which a liquid changes to a gas or vapor.
What is the most abundant gas in the Earth's atmosphere? OxygenCarbon Dioxide Nitrogen Hydrogen C) NitrogenNitrogen gas makes up approximately 78% of the Earth's atmosphere.
What is the chemical formula for water? H2O2 CO2H2ON2O C) H2OThe chemical formula for water is H2O, meaning a molecule of water consists of two hydrogen atoms and one oxygen atom.
The process of rust formation is an example of:EvaporationOxidationSublimation NeutralizationB) OxidationRust is the common name for iron oxide, a reddish-brown flaky substance formed when iron reacts with oxygen in the presence of water or air moisture. This process is called oxidation.
Which of the following is a physical change?Burning woodRusting of ironMelting iceCooking an eggC) Melting iceA physical change is a change in the form of a substance but not in its chemical composition. Melting ice is a physical change because it is still H2O in both its solid and liquid states.
What is the basic unit of a chemical element?MoleculeCompoundAtomProtonC) AtomAn atom is the smallest unit of an ordinary chemical element that contains the element's chemical properties.
Which element is the most abundant in the Earth's atmosphere?OxygenCarbonNitrogen HydrogenC) NitrogenNitrogen makes up approximately 78% of the Earth's atmosphere by volume.
What is the smallest unit of a chemical element?MoleculeCompoundAtomIonC) AtomAn atom is the smallest unit of ordinary matter that forms a chemical element.
A substance that has a pH greater than 7 is considered a(n): Acid Base (Alkaline)Neutral substanceSaltB) Base (Alkaline)The pH scale measures the acidity or alkalinity of a substance. A pH of 7 is neutral, less than 7 is acidic, and greater than 7 is basic (alkaline).
What is the chemical formula for carbon dioxide?CO O2 C2OCO2D) CO2Carbon dioxide is a naturally occurring chemical compound composed of one carbon and two oxygen atoms.
The process of a solid turning directly into a gas without passing through a liquid phase is called:Melting CondensationSublimationEvaporationC) SublimationSublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.
What is the main component of natural gas?Ethane PropaneMethaneButaneC) MethanMethane (CH4) is the primary component of natural gas, making up over 90% of its volume.
The process of a liquid turning into a gas is called:Condensation Evaporation MeltingSublimation B) EvaporationEvaporation is a type of vaporization that occurs on the surface of a liquid as it turns into the gas phase.
The chemical symbol for the element gold is: GdAuAgGoB) AuThe chemical symbol for gold, Au, comes from the Latin word "aurum," meaning gold.
What is the process of a liquid turning into a solid?MeltingFreezingEvaporationCondensation B) FreezingFreezing is the process by which a liquid turns into a solid when its temperature is lowered to its freezing point.
What is the chemical symbol for the element iron?IrFeAu In B) Fe The chemical symbol for iron is Fe, which comes from the Latin word "ferrum."
A substance that speeds up a chemical reaction without being consumed in the process is a:InhibitorCatalystReactantProduct B) CatalystA catalyst is a substance that increases the rate of a chemical reaction by providing an alternative reaction pathway with a lower activation energy.
What is the chemical formula for common salt? H2OCO2NaClC6H12O6 C) NaClThe chemical formula for common table salt is Sodium Chloride (NaCl).
The process of a gas turning into a liquid is called:EvaporationSublimationCondensationFreezing C) CondensationCondensation is the process by which water vapor or a gas changes its physical state to a liquid.
The chemical symbol for the element gold is:AgAu Fe PbB) AuThe chemical symbol for gold, Au, is derived from the Latin word "aurum."
What is the main component of vinegar?Sulfuric acidHydrochloric acidAcetic acidNitric acidC) Acetic acid Vinegar is an aqueous solution of acetic acid and other trace chemicals that may include flavorings.
What is the chemical symbol for the element iron? IrInFe AuC) Fe The chemical symbol for iron, Fe, is derived from the Latin word "ferrum."
The process of a solid turning directly into a gas without becoming a liquid is called: MeltingCondensationEvaporation SublimationD) SublimationSublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state.
What is the chemical symbol for the element sodium?SoNaNe SiB) NaThe chemical symbol for sodium, Na, is derived from the Latin word "natrium."
The process of a liquid turning into a solid is called:MeltingFreezing Evaporation CondensationB) FreezingFreezing is a phase transition where a liquid turns into a solid when its temperature is lowered below its freezing point.
The chemical symbol for the element helium is:HeHHmHiA)He The chemical symbol for helium is He. It is a noble gas and the second-lightest element.