solutions solution l a solution is a homogeneous mixture in which one substance is dissolved in...
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Solutions
Solution
A solution is a homogeneous mixture in which one substance is dissolved in another substance
Components of a solution
Two parts of a solution: the substance being dissolved (solute) and the substance doing the dissolving (solvent)
Aqueous solution
Solutions in which the solvent is water are aqueous solutions (most common)
Tinctures
A solution in which the solvent is alcohol is a tincture Ex: iodine tincture
Characteristics of a solution
Mixture of two or more substances
light passes through it particles are uniformly distributed
Ions and dissociation
Ions are atoms with a positive or negative charge
Electrolytes
Solutions that conduct electricity are electrolytes (sodium chloride and silver nitrate)
Non-electrolytes
Non-electrolytes form solutions that do not conduct electricity (sugar, alcohol, benzene)
Questions
What is a solution? What are the two parts of a solution?
What are three properties of a solution?
Questions
What’s the difference between an aqueous solution and a tincture
Question
If you wanted to dissolve a substance in water as quickly as possible what could you do?
Ways to increase dissolving rate
In order to increase the rate in which a solution dissolves one could heat the solution, stir it, or crush the solute particles
Solubility
The measure of how much solute can be dissolved in a solvent is solubility
What affects solubility?
The three main factors that affect solubility are temperature, type and the amount of the solvent
Effervescence (fizz)
The escape of a gas from a liquid is effervescence (example: soda and alka seltzer)
Concentration
Concentration of a solution is the amount of solute that is dissolved in a solvent
Concentrated vs. dilute
A solution with a lot of solute dissolved is concentrated
A solution with a little solute dissolved is dilute
Types of solutions
A saturated solution contains all the solute it can possibly hold
An unsaturated solution contains less solute that is possible
Supersaturated solution
A supersaturated solution can be made to hold more solute than is normal
Question
Compare a saturated, unsaturated, and a supersaturated solution
Questions
What is solubility and what are the three factors that affect it?
What are three ways to increase the rate in which a solute dissolves?
Water
Water is the universal solvent
A substance that cannot dissolve in water is insoluble
Polar vs. non-polar
A polar molecule has oppositely charged ends (+ and -)
Non-polar molecules have the same charges on its ends
Rule for dissolving solutes in a solvent
Like solutes dissolve in like solvents (polar in polar, non-polar in non-polar)
Hard water vs. soft water
Hard water contains dissolved metal ions
Soft water does not contain dissolved metal ions
Freezing point depression
Lowering the freezing point of a solution as a result of the dissolved solute (freezing point depression) Ex: antifreeze in water
Boiling point elevation
Raising the boiling point of a substance by adding solute (salt in water)
Questions
What is the difference between polar and non-polar molecules?
What is the general rule for dissolving solutes?
Questions
What is the difference between hard and soft water?
How does a solute affect the freezing point and the boiling point?
Suspension
A suspension is a heterogeneous mixture in which the solute particles are large enough to be seen (solute is suspended)
Colloid
A colloid is a homogeneous mixture that is not a true solution (does not separate, solute remains suspended)
Acids
Properties of an acid: sour taste, affecting the color of indicators, turn litmus paper from blue to red, pH 1-6.9
Weak acids vs. strong acids
Weak acids (pH 4 - 6.9) Strong acids (pH about 1-3; common acids: sulfuric, hydrochloric, nitric, and acetic acids
Bases
Bases are slippery, bitter taste, turn litmus paper from red to blue
pH 7.1-14
Bases
Common bases potassium hydroxide, calcium hydroxide, sodium hydroxide, and ammonium hydroxide
Weak bases vs. strong bases
Weak bases (7.1-10.9 pH)
Strong bases (11-14 pH)
pH scale Measures hydronium ion concentration (strength of the acid or base)
pH scale ranges from 0-14 (7 is the neutral point) water
Salt
Salt is a compound formed when an acid is mixed with a base (positive ion from a base and a negative ion from an acid)
Neutralization
A neutralization reaction occurs when an acid and a base combine to form salt and water
Precipitate
A precipitate is an insoluble substance crystallizes out of solution (ex: salt from a neutralization reaction)
Precipitation reaction
The process of forming a precipitate is precipitation
Questions
What is the pH scale used for?
What is the pH range for an acid, a base?
Questions
What are some properties of an acid? Of a base?
Describe neutraliztion. What is a salt?