Chemistry Reactions
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Transcript of Chemistry Reactions
Chemistry ReactionsBy: Mr. Anthony Gates
Types of Reactions
Combination (Synthesis) Reaction: chemical change in which two or more substances react to form a single new substance.
• Format:• A + B AB
• Example:
• 2 H2 (g) + O2 (g) 2 H2O (l)
Types of Reactions
Decomposition Reaction: chemical change in which a single compound breaks down into two or more simpler products.
• Format:• AB A + B
• Example:
• 2 H2O (l) 2 H2 (g) + O2 (g)
Types of Reactions
Combustion Reaction: chemical change in which an element or a compound reacts with oxygen, often producing energy in the form of heat and light.
• This change contains some form of carbon as a reactant, thus it usually produces water and carbon dioxide. If there isn’t enough oxygen, carbon monoxide may be produced instead of carbon dioxide.
• Example:
• CxHyOz + O2 CO2 + H2O + heat
Types of Reactions
Single Replacement Reaction: chemical change in which one element replaces a second element in a compound.
• Either a metal will replace a metal in a compound or a nonmetal will replace a nonmetal in a compound. A metal will not replace a nonmetal and vice versa.
• Format:• A + BC AC + B
• Example:
Inquiring minds must know…
• If a metal can replace another metal in reaction, do reactions constantly occur so long as multiple metals are present?
• No! Every element is different in structure thus each of them has a varying degree of reactivity.
• So how do we know when a metal will perform a single replacement reaction?
Activity Series
• List of metals and some nonmetals by decreasing reactivity.
• The elements that can hold onto electrons tighter are less likely to react. The more likely an element is to give up its electrons, the more reactive it is.
• Any metal will replace another metal that is below it on the activity series, but not one that is above it.
• So Iron (Fe) will replace Copper (Cu) in a reaction, but will not replace Zinc (Zn) or Calcium (Ca).
• The same pattern will occur for halogens, but only to replace another halogen.
Check Your Understanding
Will this yield a product and if so, what?
• ???
Will this yield a product and if so, what?
• ???
Types of Reactions
Double Replacement (Displacement) Reaction: chemical change involving an exchange of positive ions between two compounds.
• Format:
• AB + CD CB + AD
• Example:
• 2 NaOH (aq) + CuCl2 (aq) 2 NaCl (aq) + Cu(OH)2 (s)
Double Replacement (Displacement) Reaction
• This form of reaction usually yields one of the following types of products:
• Precipitate- a solid made that forms from an aqueous solution
• Gas
• Water
Peculiar situation
• Whenever a double replacement reaction causes Hydrogen to be paired with a carbonate ion, they will instead form carbon dioxide and water.
Solubility Rules!
• Most Nitrates ( salts are soluble
• Most salts of are soluble
• Most Chloride (, Bromide , and Iodide salts are soluble …
• Except with Silver (, Mercury , or Lead
• Most Sulfate salts are soluble …
• Except with Barium , Lead , or Calcium
Some solids just don’t want to dissolve… how rude!
• Most Hydroxide compounds are only slightly soluble
• Except for with Sodium , Potassium , Calcium
• Most Sulfide , Carbonate , and Phosphate salts are only slightly soluble
• Slightly Soluble compounds would rather stay or become a solid than be dissolved in solution… this usually causes a precipitate to form when these are created in a reaction.
Let’s simplify
• Nitrate salts are soluble
• Alkali metals and Ammonium salts are soluble
• Halogen salts are soluble except with Silver, Mercury, or Lead.
• Sulfate salts are soluble except with Barium, Lead, or Calcium.
• , and salts are NOT soluble
• Hydroxide is NOT soluble except with Calcium.
• Anything that is soluble trumps what isn’t!
Describing a Reaction
• Use your words…
• Magnesium metal reacts with hydrochloric acid to produce magnesium chloride and hydrogen gas.
• Hints:
• Write out the name of each compound.
• Who is reacting and who is being produced?
• Now write is as a sentence.
You try…
• Aluminum metal combines with oxygen gas to become aluminum oxide.
Let’s try some more…
Magnesium Chlorate decomposes into magnesium chloride and oxygen gas.
How about the Reversal
• Silver (I) Nitrate solution is added to sodium chloride to create a silver (I) chloride precipitate in a sodium nitrate solution.
• Hints:
• Draw the formulas of the compounds.
• Who is reacting and who is being produced?
• Put the formulas in order and add the appropriate symbols.
You try…
• Tetracarbon octahydrogen gas is mixed with oxygen gas to form carbon dioxide gas and water vapor.
How about some more practice?
• Beryllium metal reacts with oxygen gas to produce beryllium oxide.
Predicting Products
Combination/Synthesis:
• Two or more individual elements react to create a single product.
• A+BAB• Example:
Predicting Products
Decomposition:
• One compound breaks up into multiple compounds or elements.
• ABA+B
• Example:
•
Predicting Products
Combustion:
• Some compound (usually containing carbon and hydrogen) reacts with Oxygen to create only carbon dioxide and water.
• Example:
Predicting Products
Single Replacement:
• An individual element reacts with a compound to cause a switch between the single element and the similar part of the compound (cations with cations and anions with anions).
• A+BCAC+B
• Example:
•
Predicting Products
Double Replacement:
• Two compounds react with each other causing the anions to switch who they are bonded. This causes either a precipitate, a gas, or water to form.
• AB+CDAD+CB
• Example:• ??
Now you try…
• 2
•
How about we try some more…