Chemistry Test Grade Seven

7th Grade Chemistry: Master solutions, concentration, and chemical changes! Fun worksheets for science students.

Name: A solution that is made up of 10 % chlorophyll and 90% alcohol is: Aqueous solution Non aqueous solution Gaseous solution The soda drinks, as Pepsi, are made up of sugar and CO2 dissolved in water. This type of solution is: Aqueous gaseous solution Non aqueous liquid solution Aqueous liquid solution Given a very salty concentrated soup. In order to diluted it, you should: Add water Evaporate some water Add some salt You have the following solution that is made up of blue salt and water:To make it lighter you have to: Add blue salt Evaporate some water Add some water Given two solutions (A and B) that have the following compositions: Solution Solute (Green salt) Solvent (Water) A 80 g 250 ml B 90 g 350 mlChoose the correct statement: Solution A is lighter than solution B Solution A and solution B have the same color Solution A is darker than solution B Given three solutions A, B and C.Solution Solute SolventA 50 g of KCl200 ml of water B75g of KCl200 ml of water C25 g of KCl200 ml of waterThe solution with the smallest concentration is: A C B Khaled decided to prepare a cup of coffee; he completely dissolved 1.5 g of coffee in 400 ml. the concentration of the coffee in the water is: 0.00375 g 266.66 g 600 g Given a solution that has a concentration of 0.015 g that is made up of X g of potassium permanganate dissolved in 150 ml of water.The mass of potassium permanganate is: 0.0001 g 2.25 g 10000 g Given two solutions: S1 and S2 : SolutionKMnO4 (g)Water (ml) S1 15 150 ml S2 45 (X) ml S1and S2have the same concentrationThe volume of water in solution (S2) is: 150 ml 0.022 ml 450 ml Given a solution, that has a concentration of 0.1875 g It is made up of X g of blue salt dissolved in 400 ml of water.20 g of blue salt is added to the above solution. The new concentration is: 0.2375 g 0.05 g 75g An example on a chemical change: Melting ice cream Baking muffins Building a wooden chair from a piece of wood Lead nitrate Pb (NO3)2 reacts with potassium chloride (KCl) to produce potassium nitrate (KNO3) and lead chloride (PbCl2).The word equation of the above reaction is: Lead nitrate + Potassium chloride -> Potassium nitrate + Lead chloride Pb(NO3)2 + KCl -> KNO3 + PbCl2 Potassium nitrate + Lead chloride -> Lead nitrate + Potassium chloride Zinc carbonate ZnCO3 and potassium chloride KCl are produced when zinc chloride ZnCl2 reacts with potassium carbonate K2CO3 solution. Reactants: ZnCO3 and KCl Products: ZnCl2 and K2CO3 Products: ZnCO3 and KCl Nitric acid is liquid used in production of fertilizers and explosives. When nitric acid is added to zinc metal, a chemical reaction takes place: zinc nitrate and hydrogen gas will be formed.The sign of the given chemical reaction is: Production of hydrogen gas Production of a precipitate Change in color This change happens when sodium bicarbonate (NaHCO3) and citric acid (C6H8O7) react chemically to yield sodium citrate (Na3C6H5O7), water, and carbon dioxide gas (CO2). The temperature before the reaction was 10 OC it dropped (decreased) till 8 OC after the reaction.This reaction is: Exothermic Endothermic No exchange of thermal energy Consider the two changes that are occurring in the following lit candle:Melting the wax of the candle.Burning the wick of the candle.Choose the correct answer: Physical change: melting the wax, chemical change: burning the wick Physical change: burning the wick, chemical change: melting the wax Both changes are chemical Upon adding two colorless liquids barium chloride (BaCl2) and sulfuric acid (H2SO4), a white precipitate barium sulfate (BaSO4) and hydrogen chloride (HCl) are produced.The chemical equation of the above reaction is: Barium chloride + Sulfuric acid -> Barium sulfate + Hydrogen chloride BaCl2 + H2SO4-> BaSO4 + 2HCl BaSO4 + 2HCl -> BaCl2 + H2SO4 When a magnesium ribbon burns with oxygen gas, it produces a dazzling white flame and changes into a white powder. This powder is magnesium oxide.This reaction is: Exothermic Endothermic No exchange of thermal energy Solution A containing 30 g of copper sulfate in 100 ml water , solution B containing 40 g of copper sulfate in 100 ml water : Solution A is darker than solution B Solution A can have the same concentration as B by adding 10 g of copper sulfate to solution A. Solution B can have the same concentration as A by adding 10 g of copper sulfate to solution B. A piece of magnesium is added to a beaker containing blue copper sulfate solution. After stirring, a colorless magnesium sulfate solution and copper powder were produced.Choose the correct information related to the above reaction: Reactants: Magnesium and copper sulfateProducts: magnesium sulfate and copperEvidence of chemical reaction: change in color Reactants: magnesium sulfate and copperProducts: Magnesium and copper sulfateEvidence of chemical reaction: change in color Reactants: Magnesium and magnesium sulfateProducts:copper sulfate and copperEvidence of chemical reaction: change in color In a solution of 3 g of vinegar dissolved 50 ml of water: Solute: water, solvent: vinegar, type of solution: liquid aqueous solution Solute: vinegar, solvent: water, type of solution: liquid non aqueous solution Solute: vinegar, solvent: water, type of solution: liquid aqueous solution