Welcome to your Chemical Formulae and Chemical Equations (STUDY BY TOPICS JUNIOR CLASS) NAME EMAIL PHONE NUMBER 1. What is chemistry?The study of the properties of matter and how matter changeNone aboveThe study of matter and show matter changeThe study of ice melting from one point to other2. How many hydrogen atoms are on the product side (Left hand side)?N2 + 3H2 ----> 2NH3 SixFourThreeTwo3. Which of these is TRUE of mixtureNone of the aboveProperties are the sum of those of its individual constituentsCan be represented by a chemical formulaAlways homogenousComponents cannot be separated by physical methods4. The mixture of gases used by deep sea divers is _______Nitrogen-hydrogenHydrogen-heliumOxygen-nitrognHelium-oxygen5. Fill in the blanks:_______ cannot be created or destroyed, but can be __________ from one form to another.Liquids, changedGases, sentMatter, producedMatter, changed6. What is the LAW of Conservation of Mass?Cannot be created or destroyCan destroy or createChemical equationsChemical equation must be balanced because matter cannot be created or destoryed.7. Which of the following is a chemical change?MeltingBurningContractingFreezing8. What is the product of neutralization?SaltWaterSalt + waterSugar9. What is chemical formula?Tells the number of atoms of each element a compound. Subscrpit tells number of element in a molecuesTells the number of atoms in chemical reactionAll AboveA chemical symbol that has symbol10. What is the difference between a synthesis reactions and decomposition reactions?They are opposite of each othersSynthesis is to make or combineDecomposition is to break downAll above11. A _______ can be separated without a chemical reactionelementmixturecompoundatom12. The reaction where water is chemically broken down by passing an electric current through it, is calledelectrolysisexothermicelectronicendothermic13. Which one of the following is not a physical change?Mixing salt and pepperCutting a page in halfMaking toastMelting chocolate14. When iron rusts, the kind of change that takes place ischemicalmixturephysicalstate15. Which one of the following is a chemical equation?Ice + heat --> water Iron + oxygen --> rustCO2CO2 C + O2 --> CO2C + O2 --> CO216. Aluminum reacts with copper sulphate to produceCuO, Al2S3 and SO2Cu, Al2S3 and SO2CuO and Al2(SO4)3Cu and Al2(SO4)317. CaO- calcium Oxide reaction with water is regarded as exothermic. A student mixes these two products in a test tube and touches its side surface. Which of the following statement correctly describes the student's observation?The test tube becomes hot due to absorption of heat energyThe test tube becomes cold due to absorption of heat energyThe test tube becomes hot due to release of heat energyThe test tube becomes cold due to release of heat energy18. If the temperature of a reaction is decreased, what effect will this have on the reaction rate?It will have no effect.The rate of reaction will decrease.The rate of reaction will increase.The reaction will stop.19. Steam condensing on cold tiles is an example ofa chemical changea physical changean exothermic processan endothermic process20. Which of the following are exothermic processes- Reaction of water with quick lime Dilution of an acid Evaporation of water Sublimation of camphor crystals 1 and 22 and 31 and 43 and 421 out of 20Time is Up!
