Welcome to your Chemical Formulae and Chemical Equations (STUDY BY TOPICS JUNIOR CLASS) NAME EMAIL PHONE NUMBER 1. Which among the following are endothermic processes?i. Reaction of quick lime with water ii. Dilution acid with water iii. Evaporation of water iv. Sublimation of solid ammonium chloride (ii) and (iii) (i) and (iv) (iii) and (iv) (i) and (ii) 2. What kind of reaction occurs when the negative ions in 2 compounds switch? Double-replacement Combustion Synthesis Decomposition 3. Earth soil cannot store more nitrogen than it can hold. Hence earth soil is referred to be in a state of _________. Concentration Unsaturation Dillution Saturation 4. Steam condensing on cold tiles is an example of an endothermic process a chemical change a physical change an exothermic process 5. The mixture of gases used by deep sea divers is _______ Oxygen-nitrogn Nitrogen-hydrogen Helium-oxygen Hydrogen-helium 6. What are the coefficients of the correctly balanced equations? ----Fe2O3 + ----CO ----Fe + ---CO2 0,2,2,3 1,3,2,3 2,6,4,3 1,2,2,2 7. What is chemistry? The study of the properties of matter and how matter change The study of matter and show matter change None above The study of ice melting from one point to other 8. How many atoms of oxygen are on the left side?2H2O ---> 2H2 + O2 Four Two Three One 9. Process of evaporation increases when liquids are exposed to expansion cold heat condensation 10. 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 cold due to release of heat energy The test tube becomes hot due to absorption of heat energy The test tube becomes cold due to absorption of heat energy The test tube becomes hot due to release of heat energy 11. What is the difference between a synthesis reactions and decomposition reactions? All above Synthesis is to make or combine Decomposition is to break down They are opposite of each others 12. What is chemical formula? All Above Tells the number of atoms in chemical reaction Tells the number of atoms of each element a compound. Subscrpit tells number of element in a molecues A chemical symbol that has symbol 13. What is the product of neutralization? Salt + water Sugar Salt Water 14. Which one of the following is a chemical equation? CO2 C + O2 --> CO2 CO2 Ice + heat --> water Iron + oxygen --> rust C + O2 --> CO2 15. If two liquids are mutually soluble, they are called _______ liquids. Miscible Insoluble Immiscible Soluble 16. The reaction where water is chemically broken down by passing an electric current through it, is called endothermic exothermic electrolysis electronic 17. Which one of the following is not true for a chemical reaction Heat is usually involved. A completely new substance is formed. It can easily be reversed. It involves a change in energy. 18. Which is the BEST indication that a chemical reaction has taken place? A white substance dissolving in water Metal bubbling when placed in an unknown liquid Blue powder turns water blue Iron turning brown 19. Aluminum reacts with copper sulphate to produce Cu, Al2S3 and SO2 CuO, Al2S3 and SO2 CuO and Al2(SO4)3 Cu and Al2(SO4)3 20. You can tell a chemical reaction because it always produces … A different substance Reactants Water A change of state 1 out of 20 Time is Up! Time's up