Chemical Reactions And Equations Flashcards
(25 cards)
When can we say that a chemical reaction takes place?
When a chemical change occurs.
Lead Nitrate + Potassium Iodide
Lead Iodide and Potassium Iodide
Zinc granules + Sulphuric Acid
Zinc Sulphate and Hydrogen
What can help us determine if a chemical reaction has taken place?
+ Change in state
+ Change in colour
+ Evolution of a gas
+ Change in temperature
What are reactants?
The substances that undergo chemical change in the reaction.
What are products?
The new substances formed during the reaction.
What does the arrowhead indicate?
The direction of the equation.
What is a chemical equation?
A chemical equation is a representation of a chemical equation.
What is a skeletal equation?
A equation which is unbalanced and the mass is not the same on both sides of the equation.
What is hit-and-trial method of balancing chemical equations?
Making trials to balance the equation by using the smallest whole number co-efficient.
Solid
(s)
Liquid
(l)
Gaseous
(g)
Aqueous
Present as a solution in water; (aq)
Where are the reaction conditions indicated?
Temperature, pressure, catalyst, etc. are indication above and/or below the arrow.
What do chemical reactions involve?
Making and breaking of bonds between atoms to produce new substances.
Define combination reaction.
A reaction in which a single product is formed from two or more reactants.
OR
When two or more substances combine to form a single product.
What are exothermic reactions?
Reactions in which heat is released along with the formation of products.
Eg.: Burning of natural gas, respiration, decompostition of vegetable matter.
Define Decomposition reaction.
When a single reactant breaks down to give simpler products.
Eg.: Calcium Carbonate to Calcium Oxide and CO2.
What is thermal decomposition?
When decomposition is carried out by heating.
Eg.: Lead Nitrate heating > Nitrogen Dioxide and Lead Oxide
What is photolytic decomposition?
When chemical substances are broken down by photons.
Eg.: AgCl and AgBr > Both used in black and white photography
What are endothermic reactions?
Reactions in which energy is absorbed.
Eg.: Ammonium Chloride + Barium Hydroxide.
What is electrolytic decomposition?
Decomposition that occurs when electricity is passed through it.
Eg.: Water splits into H2 and O2 when electricity is passed through it.
What is displacement reaction?
When a more reactive metal displaces a less reactive metal from its compound.
Eg.: Iron + Copper Sulphate –> Iron Sulphate + Copper
Lead + Copper Chloride –> Lead Choride + Copper
