Unit C: Matter as Solutions, Acids and Bases: Solutions Introduction Flashcards
What is a solution?
A homogenous mixture with a uniform composition.
What is a solvent?
The substance that is present in the largest quantity, (V/M/amount).
What is a solute?
A substance that is dissolved in the solvent.
Types of Solutions
What are the types of solutions? Provide examples.
- Gas: Gas Ex: Air
- Gas: Liquid Ex: Pop
- Gas: Solid Ex: Hydrogen in Platinum
- Liquid: Liquid Ex: Alcohol in water
- Liquid: Solid Ex: Amalgrams-mercury in silver
- Solid: Liquid Ex: Sugar in water
- Solid: Solid Ex: Alloy
Types of Solutions
The substance known as the universal solvent is …and why?
Water because the majority of the time it is the solvent in a solution.
Energy and Dissolving
Forces between the particles in the solvent break which…..
…requires energy. In an ionic solid, the forces holding the ionic are together are ionic bonds. In a molecular solid, the forces holding the molecules together are intermolecular forces such as dipole-dipole bonding.
Energy and Dissolving
Some of the intermolecular forces in the solvent break. Because this breaks bonds, this means that this process…?
is endothermic.
Energy and Dissolving
Forces of attraction between the particles in the solute and the solvent result in the formation…
of new chemical bonds. This step always releases energy. Processes that release energy are called exothermic processes. For aqueous solutions, the dissolving process is called solvation or hydration.
Energy and Dissolving
Energy absorbed during the endothermic steps is considered…
to be positive and the energy released during the exothermic steps is considered to be negative.
Energy and Dissolving
The overall energy for the process is found by…
calculating the sum of the energy changed that take place during the three steps.
Energy and Dissolving
If more energy is absorbed then is released…
the process is considered endothermic. If more energy is released then is absorbed the process is considered exothermic.
What are electrolytes?
Substances that dissolve in water to form solutions that conduct electric currents
What are non-electrolytes?
Substances that do not conduct electric current when they dissolve in water.
Dissolving
What is dissolving?
When substances are dissolved in water to make aqueous solutions, the solution has the same conductivity as the solute.
Dissolving
Polar molecules tend to dissolve in water and non-polar molecules do not. Remember for molecular compounds…
like dissolves like.
Dissociation
What is dissociation?
When electrolytes dissolve in water they differ in that they break down, freeing ions, because these free ions are charged and can move around in solution, they are able to conduct electronic current.
Dissociation
In dissociation, the ionic structure is changed in that the ions are separated from each other. Provide an example.
NaCl(s) →Na+(aq) + Cl-(aq)
If the ionic compound is insoluble then the ionic compound will remain in a solid state.
Ionization
What is ionization?
When a solution forms ions.
Ionization
Some acidic compounds form ions when they are placed in water, this is called ionization. They are considered strong acids, there are six of them which include:
-Perchloric acid(HClO4)
-Hydrochloric acid(HCl)
-Hydrobromic acid(HBr)
-Hydroiodic acid(HI)
-Nitic acid(HNO3)
-Sulfuric acid(H2SO4)
All other acids stay as a molecule in solution and are considered weak acids.
Ionization
Show an example of a strong acid ionizing.
HI(aq)→H+(aq) + I-(aq)
Ionization
All other acids stay as a molecule in solution and are considered weak acids.
Show an equation for a dissolved weak acid.
H2CO3(aq)→H2CO3(aq)