Olympiad (Class 10) Chemistry — practice questions
44 free MCQs with worked solutions. Tap any question for the answer + explanation, or practice them all in the app.
Practice Olympiad (Class 10) Chemistry in the app →A student dips blue litmus paper in lemon juice and it turns red. The juice is:Red litmus paper dipped in a bitter tasting solution turns blue. The solution is a:A teacher calls litmus and turmeric natural indicators. Methyl orange is instead a:Onion and vanilla change smell in acids and bases. Such indicators are called:Zinc granules are dropped into dilute sulphuric acid. The gas that bubbles out is:A metal reacts with an acid. Besides hydrogen gas, the other product is a:Dilute acid is poured on sodium carbonate. The gas released turns lime water milky. It is:Hydrochloric acid is added to sodium hydroxide until the pink colour goes. The reaction is:Copper oxide dissolves in hydrochloric acid giving a salt and water, so metal oxides are:A mixture of several indicators showing different colours at different acidities is the:The scale that measures hydrogen ion concentration in a solution is called the:Pure water is tested with universal indicator paper. Its pH reads:A solution shows a pH of 3 on the paper. The solution is:As the hydronium ion concentration in a solution rises, the pH value:Hydrochloric acid gives far more hydrogen ions than acetic acid at equal strength. So it is a:A doctor notes the human body works only within a narrow pH range, roughly:Rain water is tested and its pH is below 5.6. This rainfall is called:Tooth enamel begins to corrode once the pH inside the mouth falls below:A dentist suggests a basic toothpaste after meals because it will:A bee sting leaves acid in the skin. Rubbing on baking soda helps because it is a mild:Blue copper sulphate crystals turn white on heating. The molecules driven off are:A doctor sets a fractured arm with a white powder that hardens with water. It is:Carbon forms four bonds because it has four valence electrons. Carbon is therefore:A bond formed when two atoms share a pair of electrons is called a:Covalent compounds conduct electricity poorly because they form no:Diamond and graphite are both made only of carbon, so they are:In graphite, each carbon atom is bonded to how many other carbon atoms?The ability of carbon to form long chains with itself is called:A compound whose carbon atoms are joined only by single bonds is called:Compared with saturated carbon compounds, unsaturated ones are generally:Two compounds share one molecular formula but differ in structure. They are:Compounds made only of carbon and hydrogen are called:Saturated hydrocarbons are known as:Hydrocarbons containing one or more triple bonds are called:The atom or group that decides the chemical properties of a carbon compound is the:A series of compounds differing by one carbon, with the same functional group, is a:Burning a saturated hydrocarbon in plenty of air generally gives a flame that is:Limiting the air supply while burning any hydrocarbon leads to:Alkaline potassium permanganate adds oxygen to ethanol. Such substances are called:Vegetable oils are turned into solid fats by adding hydrogen using a catalyst of:Ethanol is commonly known by the everyday name:Ethanoic acid, used as a preservative in pickles, is commonly called:The reaction of a fat or oil with sodium hydroxide to make soap is called:Soap used in hard water leaves an insoluble substance behind, called: