Copyright 2016 Edmentum - All rights reserved. SI: Quiz 5 Question #1 Which of the following is true about the mass of the reactants in a chemical reaction? The total mass of the reactants in a chemical reaction will never be equal to the total mass of the products. The total mass of the reactants in a chemical reaction will be significantly more than the total mass of the products. The total mass of the reactants in a chemical reaction will be significantly less than the total mass of the products. The total mass of the reactants in a chemical reaction is conserved and will be equal to the total original mass of the products. Question #2 Jayne's science teacher mixed a clear liquid with a blue liquid in a beaker. After a few minutes there was a white solid at the bottom of the beaker. What is most likely true about the white solid? It was secretly added to the beaker by the teacher. It is an organic compound. It will dissolve in water to form a blue solution.
It is a new substance with different properties. Question #3 Gerald's science teacher mixed room temperature samples of hydrochloric acid and sodium hydroxide in a large beaker. The solution still looked clear like water, but when the students carefully touched the beaker one at a time, it felt warm to the touch. Why did the beaker most likely feel warm? The release of a gas heated the solution. A chemical reaction was producing a new substance. The two liquids were not soluble in water. The energy of mixing warmed the solution. Question #4 In a chemical reaction, the total mass of the reactants is 10.0 grams. After the reaction, the total mass of the products must be: more than 10.0 grams. exactly 10.0 grams. exactly 20.0 grams. less than 10.0 grams.
Question #5 Look at the equation below. O2 + CS2 CO2 + SO2 Which of the following shows the equation balanced? 4 O 2 + 4 CS 2 4 CO 2 + 4 SO 2 O 2 + CS 2 CO 2 + SO 2 3 O 2 + CS 2 CO 2 + 2 SO 2 3 O 2 + CS 2 2 CO 2 + SO 2 Question #6 Baking soda and vinegar can be used to model a volcanic eruption in a science demonstration because they bubble violently when mixed. What can be concluded about mixing vinegar and baking soda? Vinegar boils when it comes in contact with baking soda. Vinegar and baking soda react to form a new gaseous substance. Baking soda and vinegar make a uniform mixture. Baking soda has a lower density than vinegar. Question #7 Ethanol contains the elements carbon, hydrogen, and oxygen. When ethanol burns, it chemically reacts with oxygen gas. C2H6O + ethanol O2 oxygen gas What elements will be present in the substances that are created when ethanol burns?
the elements cannot be determined carbon, hydrogen, and oxygen only carbon and hydrogen only nitrogen, sulfur, and sodium only Question #8 In the chemical reaction below, calcium (Ca) and water (H2O) react to form calcium hydroxide (Ca(OH)2) and hydrogen gas (H2). Ca (s) + 2H2O (l) Ca(OH)2 (aq) + H2 (g) Calcium and water are the reactants in this chemical reaction, whereas calcium hydroxide and hydrogen gas are the products that are formed. Once the reaction reaches completion, the total mass of the products will be equal to the original mass of the reactants. the total mass of the products will be greater than the original mass of the reactants. the products of the reaction will have changed back into the reactants. the total mass of the products will be less than the original mass of the reactants. Question #9 Over time, an iron nail reacts with water to produce iron oxide, or rust. Which of the following is a signal that rusting has taken place? the release of heat and steam at the area where the mixture occured a color change on the nail from silver to reddish-brown the release of an odor and the presence of bubbles
the appearance of sparks Question #10 According to the law of conservation of matter, which statement about chemical reactions is true? Atoms are created by some reactions and destroyed by others. Energy is created as atoms are destroyed in chemical reactions. Atoms cannot be created or destroyed by chemical reactions. Every atom destroyed in a chemical reaction must be replaced.