Exothermic releases heat; endothermic absorbs heat

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Lillian Elliott
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1 C 2 H 6 + O 2 CO 2 + H 2 O SiCl 4 + H 2 O ---> H 4 SiO 4 + HCl C + H 2 O ---> CO + H 2 2 C 2 H 6 + 7O 2 4CO 2 + 6H 2 O SiCl H 2 O ---> H 4 SiO HCl Already balanced Fe(OH) 3 ---> Fe 2 O 3 + H 2 O 2 Fe(OH)3 ---> Fe2O3 + 3 H2O Fe 3 O 4 + H 2 ---> Fe + H 2 O Fe 3 O H 2 ---> 3 Fe + 4 H 2 O Al + O 2 ---> Al 2 O 3 4 Al + 3 O 2 ---> 2 Al 2 O 3 How do you know a chemical reaction has occurred? Change in color, odor, gas produced, change in energy How is exothermic different than endothermic? Exothermic releases heat; endothermic absorbs heat What happened to the slime when you wrote your name on it and pressed it to paper? It mirrored the name back

2 Explain the Law of Conservation of Mass in terms of the Alka-Seltzer experiment. T/F: Law of Conservation of Mass only applies to chemical changes. HCl (hydrochloric acid) reacts with Na(OH) (sodium hydroxide) and has a mass of 76g. When they combine they produce NaCl and H 2 O. What is the mass of the new substance? Bag inflated due to the gas produced but did not gain or lose mass 76 grams

3 C 2 H 6 + O 2 CO 2 + H 2 O SiCl 4 + H 2 O ---> H 4 SiO 4 + HCl C + H 2 O ---> CO + H 2 2 C 2 H 6 + 7O 2 4CO 2 + 6H 2 O SiCl H 2 O ---> H 4 SiO HCl Already balanced Fe(OH) 3 ---> Fe 2 O 3 + H 2 O 2 Fe(OH)3 ---> Fe2O3 + 3 H2O Fe 3 O 4 + H 2 ---> Fe + H 2 O Fe 3 O H 2 ---> 3 Fe + 4 H 2 O Al + O 2 ---> Al 2 O 3 4 Al + 3 O 2 ---> 2 Al 2 O 3 How do you know a chemical reaction has occurred? Change in color, odor, gas produced, change in energy How is exothermic different than endothermic? Exothermic releases heat; endothermic absorbs heat What happened to the slime when you wrote your name on it and pressed it to paper? It mirrored the name back

4 Explain the Law of Conservation of Mass in terms of the Alka-Seltzer experiment. T/F: Law of Conservation of Mass only applies to chemical changes. HCl (hydrochloric acid) reacts with Na(OH) (sodium hydroxide) and has a mass of 76g. When they combine they produce NaCl and H 2 O. What is the mass of the new substance? Bag inflated due to the gas produced but did not gain or lose mass 76 grams

5 or chemical: Heat changes H 2 O to steam. or chemical: You toast a piece of bread for too long and it is black and the kitchen is filled with smoke. or chemical: Baking powder reacts with yeast to produce CO 2

6 Name the compound: Name the compound: nitrogen trichloride Name the compound: OF 2 Al 2 (CO 3 ) 3 Aluminium Carbonate NCl 3 Oxygen difluoride Name the compound: AlCl 3 Aluminium Chloride Name the compound: Be 3 P 2 Beryllium Phosphide Name the compound: Li 2 (SO) 4 Lithium Sulfate

7 Which can be broken down further? An element or compound? Compound T/F: When elements combine to make a compound they keep their same properties T/F: The ammonium nitrate cold pack was a chemical change. With the elephant toothpaste demo it was what type of reaction: exothermic or endothermic? Exothermic (heat was released) T/F: When an item gets heavier in mass, it is the exception to the Law of Conservation of Mass. While enjoying ice tea, a student notices that the color of the drink changes as the ice melts. This is a physical or chemical change? or chemical: Table salt dissolves in water. or chemical: Wood rots. or chemical: A tire inflates.

8 or chemical: Heat changes H 2 O to steam. or chemical: You toast a piece of bread for too long and it is black and the kitchen is filled with smoke. or chemical: Baking powder reacts with yeast to produce CO 2 Name the compound: Name the compound: nitrogen trichloride Name the compound: OF 2 Al 2 (CO 3 ) 3 Aluminium Carbonate NCl 3 Oxygen difluoride Name the compound: AlCl 3 Aluminium Chloride Name the compound: Be 3 P 2 Beryllium Phosphide Name the compound: Li 2 (SO) 4 Lithium Sulfate

9 Which can be broken down further? An element or compound? Compound T/F: When elements combine to make a compound they keep their same properties T/F: The ammonium nitrate cold pack was a chemical change. With the elephant toothpaste demo it was what type of reaction: exothermic or endothermic? Exothermic (heat was released) T/F: When an item gets heavier in mass, it is the exception to the Law of Conservation of Mass. While enjoying ice tea, a student notices that the color of the drink changes as the ice melts. This is a physical or chemical change? or chemical: Table salt dissolves in water. or chemical: Wood rots. or chemical: A tire inflates.

Name: Thermochemistry. Practice Test C. General Chemistry Honors Chemistry

Name: Thermochemistry. Practice Test C. General Chemistry Honors Chemistry Name: Thermochemistry C Practice Test C General Chemistry Honors Chemistry 1 Objective 1: Use the relationship between mass, specific heat, and temperature change to calculate the heat flow during a chemical