Go to the Quizzes Page Chemical Reactions 0% 3 Created by AbuBakrShalabi Please write your name and email to receive your certificate. 1 / 20 A student mixed two chemicals to allow them to react. The temperature before the reaction was 25 ° C. The temperature after the reaction was 18° C. Which of the following is true? Energy is released from the reaction into the surrounding. It is an exothermic reaction It is an endothermic reaction The temperature did not change. 2 / 20 Which are the reactants? O and MgO Mg and O Mg and MgO MgO 3 / 20 How many total atoms are in this compound? 2 6 3 5 4 / 20 If a chemical reaction is EXOTHERMIC, the temperature would.... Stay the same Change in shape Decrease Increase 5 / 20 What is the left part of a chemical equation called? Reactants Products Chemical Equation Yields 6 / 20 When a copper wire was dipped into a beaker containing a colorless solution, the solution turned blue and the beaker felt warmer. Which statement is TRUE about the type of this chemical reaction? exothermic reaction, because thermal energy was absorbed endothermic reaction, because thermal energy was absorbed exothermic reaction, because thermal energy was released endothermic reaction, because thermal energy was released 7 / 20 Which statement is not a description of a chemical reaction? A liquid is heated in the sun and half of it evaporates. A solid is dropped into a beaker of liquid and an explosion occurs. A solid is dropped into a beaker of liquid and a gas is released. Two liquids are mixed in a beaker and a solid forms at the bottom of the beaker. 8 / 20 In order for an equation to be balanced, there must be ... an equal amount of atoms on both sides a greater mass on the reactant side elements with the same atomic # on both sides a greater mass on the product side 9 / 20 How many atoms in all are in a molecule of serotonin? C10H12N2O 10 12 25 4 10 / 20 Which of the following models best demonstrates a balanced chemical equation? H G J F 11 / 20 What is the right part of a chemical equation called? Chemical Equation Yields Reactants Products 12 / 20 Check ALL the boxes that show the signs of a chemical change. smell color change air gas (bubbles) produced 13 / 20 During a reaction, atoms are rearranged created destroyed 14 / 20 Which is NOT an indication of a chemical change? Temperature Change Shape Change Production of light Formation of a precipitate 15 / 20 Which is an example of a chemical reaction? cookies baking in an oven paper cut into small pieces flour and sugar mixed in a bowl chocolate melting in a pan 16 / 20 In an endothermic reaction, energy is _________. absorbed released stay the same in random directions 17 / 20 A chemical reaction is when... Atoms and molecules are destroyed Atoms and molecules break apart and regroup to form new products Atoms and molecules are created 18 / 20 The law of conservation of mass states that _________. the total mass of the reactants equals the total mass of the products the total mass of the reactants is greater than the total mass of the products the total mass of the reactants is less than the total mass of the products the mass is not conserved 19 / 20 In a chemical reaction, 4 grams of sodium must combine with how many grams of chlorine to produce 10 grams of table salt? 8 grams 10 grams 4 grams 6 grams 20 / 20 The reactants in the image above are: All of these are reactants 2 H2O and CO2 All of these are products CH4 and 2 O2 Your score is 0% Restart quiz Go to the Quizzes Page