Chemical Reactions Flashcards
What is a physical change
A change where the molecules do not undergo any change
What is a chemical change
A change that results in the rearrangement of the atoms of the combining substances to form new substances
When does an exothermic reaction
When energy is released during a chemical reaction (the energy of the reactants is greater than the energy of the product.
What is an endothermic reaction
Energy is absorbed during a chemical reaction. (The energy of the reactants is less than the energy of the product)
What is a chemical reaction
A way to describe what happens during a chemical change
What is delta heat
Energy of products - energy of reactants
What is an electrolyte
A solution that contains ions and can conduct electricity
What does the conductivity of a substance depend on
The type of substance, the concentration of the ions in solution and the solubility of a certain substance
What are the three types of ion exchange reactions
Precipitation, gas forming and acid-base reactions
What is a precipitation reaction
When aqueous solutions of certain salts are mixed and an insoluble product (solid) suddenly forms in the mixture
What is a solution
A homogenous mixture of a solute and a solvent
What is a solute
The substance that is being dissolved in the solution
What is a solvent
The substance in which the solute is being dissolved to form a solution
What is a saturated solution
A chemical solution containing the maximum concentrations of a solute dissolved in the solvent
What is concentration
The amount of solute per unit volume of solution
What is a precipitate
The solid that forms in a solution during a chemical reaction
What is suspension
A heterogeneous mixture of a solid suspended in a liquid
What is hydration
Where ions become surrounded by water molecules in a water solution
What dissolves in water
Ions and polar substances
What’s the difference between dissociation and ionisation
Dissociation water is a solvent so it’s written above the arrow whereas ionisation water is a reactant to form ions in solution. And also dissociation occurs when with ionic compounds and ionisation occurs with polar covalent compounds
What is an electrolyte
A solution that contains free moving ions
What is a strong electrolyte
A substance whose aqueous solution is a good conductor.
What are non electrolytes
Molecules because they do not dissolve in water
What is % yield
The Measure of the extent of a reaction, generally measured by comparing the amount of product produced against the amount of product possible
