1 A solid that forms from a solution during a chemical reaction is called a __________.A) precipitate B) substrate C) reactant D) formate 2 What is the missing product in this balanced equation describing the decomposition of water? 2H2O(l) + energy → O2(g) +A) 2H2 (g) B) H2 O(g) C) H2 (g) D) energy 3 If a lump of coal contains 200 billion carbon atoms and it burns completely, how many oxygen molecules will it consume? (18.0K)A) 50 billion B) 100 billion C) 200 billion D) 400 billion 4 In the reaction of aluminum powder and iron oxide (called the thermite reaction), aluminum oxide is the __________.A) reactant B) precipitate C) catalyst D) product 5 A word equation includes both __________ and __________, separated by an arrow.A) catalysts, precipitates B) reactants, products C) reactors, producers D) matter, energy 6 In the reaction of aluminum powder and iron oxide (called the thermite reaction), a great quantity of heat is released. This reaction is said to be __________.A) endothermic B) exothermic C) hydrothermic D) polythermic 7 A particular reaction is performed in an erlenmeyer flask. Afterwards, the flask is frozen to the laboratory table. Most likely, the reaction was __________.A) endothermic B) exothermic C) hydrothermic D) polythermic 8 In photosynthesis, sugar and oxygen are formed from water and carbon dioxide. What else must appear in the equation, and where does it appear?A) energy, with the products B) energy, with the reactants C) chlorophyll, with the products D) chlorophyll, with the reactants 9 In a balanced equation, the number of atoms on the left side of the equation is __________ the number of atoms on the right side of the equation.A) either greater than or less than B) always greater than C) always less than D) always equal to 10 Hydrogen peroxide is stored in brown containers because in sunlight it changes into oxygen and water. What class of reaction is this?A) decomposition B) synthesis C) double displacement D) single displacement 11 In the reaction of aluminum powder and iron oxide (called the thermite reaction), the products are aluminum oxide and molten iron. What class of reaction is the thermite reaction?A) decomposition B) synthesis C) double displacement D) single displacement 12 A substance that slows down a reaction is called a(n) __________.A) catalyst B) enzyme C) inhibitor D) reactant 13 What is one way to slow down reaction rate?A) lower the temperature B) increase the surface area C) use a catalyst D) increase the concentration 14 In the Haber process for making ammonia, gas pressure is kept very high. Why?A) High pressure lowers the temperature. B) High pressure increases the concentration of reactants. C) High pressure acts as an inhibitor. D) High pressure increases the activation energy. 15 Hydrogen and oxygen can exist in the same container for years without reacting. What do they require to react?A) activation energy, such as a spark B) a catalyst C) an inhibitor D) high pressure