C SMA Kr. IntanPermataHati Jl. Raya KedungBaruk 112 – 114 Surabaya Final Examination Semester 2 Subject Time Class Name Year 2021 – 2022 : SCIENCE BIO-CHEM : 60 minutes : VII C : Cailyn Stephanie Runtukahu ………………………………. SCORE INSTRUCTION - - - ANSWER ALL THE QUESTIONS CORRECTLY YOU MAY MAKE YOUR OWN ANSWER SHEET, BUT PREFERABLY ANSWER THE QUESTIONS IN THE SPACE PROVIDED, USING A DIFFERENT COLOUR OR BOLD YOUR ANSWER. YOU MAY PRINT THE QUESTION PAPER AND DO IT MANUALLY, BUT DON’T FORGET TO TAKE PICTURES OF YOUR ANSWER SHEET AND UPLOAD IT IN GC DON’T FORGET TO CLICK TURNED IN ONCE YOU ARE DONE. 1 STRUCTURED QUESTIONS (50 POINTS) 1. Choose one metal from the list below to match its properties. The word can only be used once. Silver steel a. b. c. d. e. f. aluminium stainless steel copper mercury Liquid metal at room temperature Mercury Malleable, shiny use in jewelerries Silver Ductile, conducts electricity use in electrical wiring Copper Does not rust easily use in cooking utensils Stainless steel Heavy strong metal use in bridges Steel Light weighted metal use to keep food warm Aluminium (6 points) 2. Universal indicator is used to measure the pH of a substance. In a neutral solution which has a pH of 7 will turn green , but in a substance with pH of 13 it will be Violet in colour. However litmus is a dye made from living organism. It is Red in acid and blue in alkali. When litmus paper changes colour we can say that a Chemical reaction has taking place. (5 points) 3. Give 1 reason why you don’t burn your hand when picking up a metal saucepan with a wooden handle? Because wooden handle doesn’t conduct heat energy so it wont burn your hand when your picking up the saucepen Suggest what could be done if there is an accident and some acids is spilt on a bench in a laboratory? Directly clean it using cloth because some acid is corrosive and if you use tissue it might burn (3 points) 4. Choose the best separating techniques from the words in the box below for questions a-d chromatography magnet filtration sieve evaporation distillation 2 a. sand in a salt water solution? Filteration (to separate salt from the mixture) b. iron filling in mixture of sand, paper bits and pebbles Magnets for separating iron from mixture c. copper sulphate crystals and pieces of glass. Sieve d. different colours from a black ink? Chromatography ( 4 points) 5. The diagram shows an experiment where zinc metal is added to hydrochloric acid showed in a sequence of A-C A B C Complete the statement below a. Comple the equation in tube A Zinc + hydrochloric acid Zincloride+ Hydrogen b. What is the name of the gas given off in this reaction? Hydrogen c. Explain what is happening in tube B? hydrogen gas burn with a squeeky pop d. What is the result in tube C? Reaction take place because there is the pop sound. When the hydrogen pops, reacting with oxygen with the air from water. 6. ( 5 points) Write the following whether it is a physical change or chemical reaction. 3 a. b. c. d. e. Leaf turning yellow : Chemical change Ice cream melting : Physical change Blasting fireworks : Chemical change Glass crackling after heating it : Physical change Frying an egg : Chemical changes (5 points) 7. Magnesium ribbon burns in the air a. What is the chemical symbol for magnesium Mg b. Mention one other metal and its symbol Potasium, K c. Name the element in the air that reacts with magnesium when it burns. Oxygen d. Name the compound formed when this element reacts with magnesium . Magnesium Oxide (MgO) e. Magnesium also reacts with fluorine. Write the equation and name the reactant and the product. Magnesium+Florine magnesium floride+ Water f. What is one safety precautions you need to take while carrying out this experiment (burning magnesium ribbon) Wear safety goggles and don’t look directly at the flame 8. (6 points) Give two differences between virus and bacteria 1. Viruses might be smaller than bacteria 2. Bacteria can be healed with antibiotics while virus cant Make a food chain that includes microorganism as decomposers. You don’t have to draw pictures – just write the names. Grass Grasshopper frog snake eagle decomposers (4 points) 9. Some bacterias are decomposers. They break down food and change it. Usually this makes the food unpleasant, but sometimes it changes it to something that is good to eat like yogurt. 4 Questions a. Mention one way we can slow down decomposition Make the temperature lower b. Beside rotting food mention one other negative effect of bacterias. Cause dieseas c. Explain why it is a good idea to wash containers before making yogurt. So there is no bacteria in the container d. Mention one other advantage of microorganism beside being a decomposer. Can be use to make antibiotic or medicine (4 points) 10. Complete the chemical reactions below a. Tin + hydrochloric acid Tin chloride + hydrogen b. Magnesium + Sulfur Magnesium sulphate + Oxygen c. Sulphuric acid + lithium hydroxide d. Hydrochloric acid + hydroxide+ water e. Calcium + water f. Zinc + Water g. carbon + oxygen Lithium sulphate + water sodium hydroxide sodium calcium hydroxide + hydrogen zinc hydroxide + Hydrogen carbon oxide h. Lithium + Oxygen lithium oxide 5