Flashcards in Chapter 22: Mixtures: Solutions, Colloidal Dispersions, and Suspensions Deck (73)
Most foods are complex mixtures of what?
Most foods are complex mixtures of many types of elements and compounds
- understanding how components interact helps predict how foods will react during processing
What is the Dispersed Phase?
refers to the particles scattered throughout the medium
What is the Continuous Phase?
is the medium in which particles are distributed
How are Food Mixtures classified?
Food Mixtures are classified by the size of particles distributed throughout the mixture
How big are the particles in solutions?
Solutions have the smallest particles
How big are the particles in Colloidal Dispersion?
Colloidal Dispersions have particles larger than those in solutions
How big are the particles in Suspensions?
Suspensions have the largest particles
What is a solution?
A solution is homogenous mixture of 2 or more substances
1. The dispersed phase is the solute
2. The continuos phase is the solvent
3. Particles are small and have a high level of kinetic energy
4. Solutions cannot form gels
Solutions are possible in any combination of the 3 states of matter, the most common types of solutions are?
1. Solids in liquids (Salt or Sugar in water)
2. Liquids in liquids (flavouring and vinegars)
3. Gas in Liquids (carbonated beverages)
What is Solubility?
Solubility describes the amount of the solute that will dissolve in a solvent
What is Le Chatelier's Principle?
states that when the chemical equilibrium changes, the equilibrium shifts to counteract the change
Solubility is affected by what?
temperature, particle size, concentration, pH, agitation and vapour pressure
The solvents temperature affects the solubility of solids by..?
1. The amount of solid solute that a solvent will hold increases as temperature increases
2. A solid dissolves faster if more molecules of the solid
3. In candy production, as water heats it can hold more sugar solute
The Solvents temperature affects the solubility of gases?
1. The amount of gaseous solute that a solvent holds decreases as temperature increases which is why soft drinks lose their carbonation faster at room temperature
2. The more the gas molecules move, the less energy it takes for the gas to escape
The smaller the solute's particles are, the greater what?
The smaller the solute's particles are, the greater is the exposed surface area and the faster the solute will dissolve
What is Concentration?
concentration is the measure of parts of one substance (solute) to the known volume of another (solvent)
What does unsaturated mean?
A solution that can dissolve more solvent at a given temperature is unsaturated
What does saturated mean?
A solution holding all the solute that will dissolve in a solvent at any given temperature is saturated
Intermolecular bonding plays a key role in concentration by..?
1. Hydrogen bonds form when water comes close to other polar molecules
2. Heat breaks bonds in the solute, allowing the solution to hold more solute
What is a saturation Point?
When all water molecules have bonded to a solute, a solution is at the saturation point
What does Supersaturated solution mean?
If the solution is heated then cooled, a supersaturated solution forms
Singly charged ions tend to be more what?
Singly charged ions tend to be more soluble than ions with 2 or more charges
Smaller ions are more what?
Smaller ions are more soluble than larger ions
- Calcium carbonate, a compound used in calcium supplements, dissolves slowly in neutral water, but quickly when an acid is added
How does Agitation affect Solubility?
Agitation or stirring speeds the dissolves rate until the saturation point is reached
- Agitation also adds a small amount of energy that slightly raises the temperature
How does Vapour Pressure affect solubility?
Vapour pressure is
1. The pressure at which gases escape from and dissolves into a liquid at the same rate
2. Important in maintaining gases in solution
Gas concentration in a liquid directly relates to what?
Gas concentration in a liquid directly relates to pressure of the gas over the liquid
Fizz in carbonated drinks occurs because of what?
Fizz in carbonated drinks occurs because gas is added to liquid under pressure
What is Mass percent?
is the percentage of the mass in a solution that comes from the solute
- The mass of the solute is divided by the total mass of the solution multiplied by 100
(mass of solute/mass of solution X100) = mass percent
When solutes are added to water what happens?
When solutes are added to water, the freezing point drops and boiling point rises
- The change is greater as the mass percent of solute the solute increases