Solutions Flashcards
Matter:
Anything with mass and volume.
Substance:
Matter with constant composition. All particles have the same properties. Eg. Water, helium
Mixture:
Matter with variable composition, made from two or more substances. Eg. Sand, soil
Element:
A substance made of atoms with the same atomic number. Eg. Lead, sodium
Compound:
A substance made from two or more elements chemically combined. Eg. Carbon dioxide
Homogenous Mixture:
A mixture made up of particles that are uniformly distributed. Eg. Saltwater
Heterogeneous Mixture:
A mixture made up of particles that are not uniformly distributed. Eg. Raisin bran
Solution:
Formed by dissolving a solute into a solvent.
Solute:
The dissolved substance in a solution which may be solid, liquid, or gas.
Solvent:
The medium containing a solute which can be any state of matter.
True or false: All mixtures are solutions but not all solutions are mixtures
False.
True or False: Not all mixtures are solutions, but all solutions are mixtures.
True.
Why is water a common solvent?
Because it is a polar molecule.
Hydration:
When H2O molecules gradually surround the ions.
Dissociation:
The separation of ions from each other.
Solvation:
The surrounding of solute particles by solvent.
The dissolving process:
Molecules become more spread out, energy is lost or gained.
Is dissolving a chemical or physical change?
Physical
The steps of dissolving:
The solute breaks (endothermic), the solvent breaks (endothermic), the particles of both attract and create solvent bonds (exothermic).
Miscible:
Liquids that dissolve in each other in all proportions.
Immiscible:
Liquids that do not dissolve in other liquids at all.
What is saturation at a molecular level?
Ions are crystallizing at the same rate that solid crystals dissolve.
Electrolytes:
Solutions that conduct electricity and must contain ions.
Factors that affect the rate of dissolving:
Particle size, temperature, nature of the particle, agitation/stirring.
Factors that affect the solubility of substances in a solvent:
Temperature, pressure, miscibility.
What factor most affects the solubility of a solid?
Temperature.
What factor most affects the solubility of a gas?
Pressure.
High solubility ionic compounds and bases dissociation:
Will dissociate into two ions when placed in water.
Low solubility ionic compounds and bases dissociation:
Will not dissolve or dissociate in water.
Strong Acids:
The 6 strong acids ionize completely to produce hydrogen ions and an anion
Weak acids:
Do not ionize completely in water.
High solubility molecular compound solubility:
Dissolve in water but do not dissociate
High solubility molecular compounds:
H bonded compounds and sugar, group 17 elements.
Low solubility molecular compound solubility:
Do not dissolve in water and do not dissociate.
Low solubility molecular compounds:
No h-bonds.
How to calculate grams per litre:
mass of solute/volume of solute
How to calculate percent by mass (%m/v):
mass of solute (g)/volume of solution (mL) x 100
How to calculate parts per million (ppm):
mass of solute (g)/volume of solution (mL) x 1000000
How to calculate molar concentration (mol/L):
moles of solute (mol)/volume of solution (L)
How to calculate mole ratio:
moles of required/moles of given
What are the steps for preparing a solution?
- Calculate the required mass of solute
- Weigh (x) grams of solute and put in a clean, dry beaker
- Dissolve (x) grams with half the amount of the final volume of distilled water
- Transfer the solution into a volumetric flask using a funnel and rinse everything out
- Fill the volumetric flask up to the line with an eyedropper
- Stopper and invert.
What is the formula for dilution?
C1V1 = C2V2
What are the steps for the preparation of a solution by the dilution of a solution of higher concentration?
- Calculate the volume of concentrated solution required
- Transfer the concentrated solution into a dry beaker. Use a graduated cylinder for measuring (x) millilitres of concentrated solution
- Pipet the solution into a clean, dry 100 mL volumetric flask
- Add distilled water to the line using an eyedropper
- Stopper and invert
When writing the equations for a chemical reaction, what are the three different steps?
Nonionic, total ionic, and net ionic.