Welcome to your Chemical Formulae and Chemical Equations (STUDY BY TOPICS JUNIOR CLASS) NAME EMAIL PHONE NUMBER 1. What is the product of neutralization? Salt Sugar Salt + water Water2. Which of the statements about the reaction below are incorrect? 2PbO(s) + C(s) → 2Pb(s) + CO2 (g) i. Lead is getting reduced. ii. Carbon dioxide is getting oxidized. iii. Carbon is getting oxidized. iv. Lead oxide is getting reduced. (i), (ii) and (iii) (i) and (ii) (i) and (iii) (iv) only3. Which of these is TRUE of mixture Components cannot be separated by physical methods None of the above Can be represented by a chemical formula Always homogenous Properties are the sum of those of its individual constituents4. A _______ can be separated without a chemical reaction compound atom element mixture5. What is matter that is made up of only one kind of atom called? Element Mixture Gas Compound6. The components elements of soap are sodium, oxygen, carbon and hydrogen water, sodium, oxygen and hydrogen carbon, hydrogen and oxygen silicon and oxygen calcium, carbon and oxygen7. Which of these is a compound? Gold Rust Salt water Fruit salad8. You can tell a chemical reaction because it always produces … Reactants Water A change of state A different substance9. What is the LAW of Conservation of Mass? Can destroy or create Chemical equations Chemical equation must be balanced because matter cannot be created or destoryed. Cannot be created or destroy10. In a chemical reaction, the substances that react together are called the products the processes the reactants the chemicals11. Which of the following is a chemical change? Contracting Freezing Melting Burning12. Which of the following factors does NOT affect the rate of a chemical reaction? Size of the reactants Colour of the reactants Temperature of the reactants Number of particles reacting13. Which one of the following factors increases the reaction rate? Placing the reactants in the dark Diluting the reactants Lowering the temperature of the reacting particles More collisions between the reacting particles14. Aluminum reacts with copper sulphate to produce CuO, Al2S3 and SO2 Cu, Al2S3 and SO2 Cu and Al2(SO4)3 CuO and Al2(SO4)315. Zinc + Sulphuric acid → Zinc sulphate + (X) What will be the product "X"? Nitrogen Hydrogen ZnO Zinc Sulphite16. What happens when dilute HCl is added to iron filings? Chlorine gas and iron hydroxide are produced. Iron salt and water are produced. Hydrogen gas and iron chloride are produced. No reaction takes place.17. Which one of the following is not a physical change? Cutting a page in half Melting chocolate Mixing salt and pepper Making toast18. 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 release of heat energy The test tube becomes cold due to absorption of heat energy The test tube becomes hot due to absorption of heat energy The test tube becomes cold due to release of heat energy19. What are the coefficients of the correctly balanced equations? ----Fe2O3 + ----CO ----Fe + ---CO2 2,6,4,3 0,2,2,3 1,2,2,2 1,3,2,320. How many atoms of oxygen are on the left side?2H2O ---> 2H2 + O2 Four Three Two One21 out of 20Time is Up!
