Welcome to your Chemical Formulae and Chemical Equations (STUDY BY TOPICS JUNIOR CLASS) NAME EMAIL PHONE NUMBER 1. Adding sugar to a cup of tea is a physical change becausethere is no change in temperaturethe tea tastes sweeterit is possible to separate the sugar from the teathere is no change in colour2. How many atoms of oxygen are on the left side?2H2O ---> 2H2 + O2OneThreeFourTwo3. What is matter that is made up of only one kind of atom called?GasElementMixtureCompound4. Which of the following factors does NOT affect the rate of a chemical reaction?Colour of the reactantsNumber of particles reactingSize of the reactantsTemperature of the reactants5. Which of the following is a chemical change?BurningMeltingFreezingContracting6. Which one of the following is a chemical equation?C + O2 --> CO2CO2 C + O2 --> CO2CO2Ice + heat --> water Iron + oxygen --> rust7. A true solution is a homogeneous mixture of solute and solvent. Chalk powder in water is a heterogenous mixture. Is it a true solution?Yes. it is a true solution.No. it is not a true solution. It is called SuspensionNo. it is a true solution.No. it is not a true solution. It is called Colloid.8. In a chemical reaction, the substances that react together are calledthe processesthe productsthe reactantsthe chemicals9. Which is the BEST indication that a chemical reaction has taken place?A white substance dissolving in waterMetal bubbling when placed in an unknown liquidBlue powder turns water blueIron turning brown10. Which of the following are exothermic processes- Reaction of water with quick lime Dilution of an acid Evaporation of water Sublimation of camphor crystals 2 and 31 and 23 and 41 and 411. Which one of the following is not a physical change?Melting chocolateCutting a page in halfMaking toastMixing salt and pepper12. When iron rusts, the kind of change that takes place ischemicalphysicalstatemixture13. A _______ can be separated without a chemical reactioncompoundelementmixtureatom14. Aluminum reacts with copper sulphate to produceCu and Al2(SO4)3Cu, Al2S3 and SO2CuO and Al2(SO4)3CuO, Al2S3 and SO215. What happens when dilute HCl is added to iron filings?Iron salt and water are produced.No reaction takes place.Chlorine gas and iron hydroxide are produced.Hydrogen gas and iron chloride are produced.16. People often hang their clothes out to dry. This is an example ofcondensationfreezingmeltingsublimationevaporation17. The components elements of soap arecarbon, hydrogen and oxygensilicon and oxygensodium, oxygen, carbon and hydrogenwater, sodium, oxygen and hydrogencalcium, carbon and oxygen18. If two liquids are mutually soluble, they are called _______ liquids.MiscibleSolubleImmiscibleInsoluble19. Respiration is an important chemical reaction that takes place in plants and animals. This process may be represented by a chemical equation. Fill in the blanks in this equation: Glucose + Oxygen → _______ + _________Air + WaterCarbon dioxide + WaterCarbon dioxide + AirWater + Nitrogen20. Which one of the following factors increases the reaction rate?Lowering the temperature of the reacting particlesMore collisions between the reacting particlesDiluting the reactantsPlacing the reactants in the dark21 out of 20Time is Up!
