Chapter Four-Solutions and Solubility Flashcards
Define solvent.
Any substance that has other substances dissolved in it.
Fill in the blanks. A solution is a __________________, meaning it is _____________ throughout.
A) Homogeneous mixture
B) Uniform
Define solute.
Substances that are present in the solution.
Define variable composition.
Different ratios of solvent to solute.
Does a chemical rxn occur when a solute dissolves in a solvent?
No.
What states can a solution occur in?
A solution can be a gas, liquid or solid.
Describe the difference b/w sq and solid solutions.
Aqueous solutions: water is the solvent, liquids where any amount dissolved in water are miscible (ethanol and water) , liquids that do not relatively dissolve in each other are immiscible (oil and water). Solid solutions (alloys): adding small quantities of another element to a metal, which in turn, changes its properties. Ex. Copper+Tin=Bronze
Describe the solubility of a solute.
It is the amount of solute that dissolves in a given quantity of a solvent at a certain temperature.
Describe saturated solution.
It is formed when no more solute will dissolve in a solution, and excess solute is present.
Describe unsaturated solution.
A solution that is not yet saturated, can dissolve more solute.
State the three factors that affect the rate of dissolving.
Temperature: rate of dissolving is greater at higher temperatures (greater Ek=colliding)
Agitation: by stirring or shaking container increases dissolving (brings into contact)
Particle size: decreasing the particle size will increase the rate of dissolving (sugar cube vs packet, increase SA that is in contact with solvent)
Fill in the blanks. When the forces of attraction b/w different particles in a mixture are ___________ than the forces of attraction between like particles in the mixture, a ___________ forms. The strength of each attraction influences ________________ or the amount of solute that dissolves in a __________.
A) Stronger
B) Solution
C) Solubility
D) Solvent
Fill in the blanks. The process of Dissolving at the Molecular Level: The forces b/w the particles in the solid must be ____________. This step always requires ______________. In an ionic solid, the forces that are holding the ions together must be _________________. In a molecular solid, the forces b/w the molecules must be __________. Some of the intermolecular forces b/w the particles in the liquid must be ________. This step also requires __________. There is an attraction b/w particles of the solid and particles of the liquid. This step always gives off _________.
A) Broken B) Energy C) Broken D) Broken E) Broken F) Energy G) Energy
True or False. Polar compounds dissolve in polar solvents and DO NOT dissolve in non-polar solvents.
True.
True or False. Non-polar compounds dissolve in polar solvents, and DO NOT in non-polar solvents.
False. Non-polar compounds dissolve in non-polar solvents, and DO NOT in polar solvents.
What is a dipole?
Two opposite charges that are separated by a short distance.
What is a dipole-dipole attraction?
The attraction b/w opposite charges on 2 different polar molecules. (intermolecular b/w molecules, in water,, hydrogen bonding; it occurs b/w the oxygen atom on one molecule and the hydrogen atoms on a nearby molecule, 1% as strong as ionic or covalent bond hydrogen bonding is much stronger than ordinary d-d attraction)
Describe Ion-Dipole Attractions.
Ionic crystals consist of repeating patterns of oppositely charged ions when they come into contact w/ water, the - end of dipole on some water molecules attracts the cations on the surface of the ionic crystal. At the same time, the + end of water dipole attracts anions. ATTRACTIVE FORCES B/W ION AND A POLAR MOLECULE an ionic compound will dissolve in a polar solvent, when ions are hydrated they will conduct electricity=electrolyte)
Describe the exception of Insoluble Ionic Compounds
Attraction b/w ions is difficult to break, compounds w/ very strong ionic bonds tend to be less soluble in water than compounds with weak ionic bonds.
How do you predict the solubility of a binary compound?
You must determine the electronegativity of each element; a big difference between these values will allow you to see it is ionic or polar (dissolves in water) and a small difference between these values will allow you to see it is nonpolar (does not dissolve in water).
Fill in the blanks. Covalent compounds do not have the _________________ or ______________ to attract water molecules. Methanol, ethanol and sugars are extremely soluble, they ____________________ because their molecules contain _______________, which are able to form _____________ with water.
A)Positive charges B)Negative charges C)Dissolve D)Polar bonds E)Hydrogen bonds
How do sucrose molecules dissolve?
They have a number of sites that can form hydrogen bods with water to replace the attraction between sucrose molecules. They separate and become hydrated like dissolved ion molecules that remain neutral, no current, non-electrolytes.
True or False. Benzene and Kerosene are non-polar solvents; therefore, they can dissolve non-polar solvents.
True.
Did you know? Forces between the solute molecules are replaced by forces b/w the solvent and solute molecules?
Because you should!
Fill in the blank. Ionic solutes and polar covalent solutes dissolve in _______________________.
Polar solvents
If a compound has both polar and non-polar components can it dissolve in both mediums?
Yes
What state does pressure have an effect on solubility?
In a gaseous state
What is heat pollution?
Water used to cool down machinery and is released into local lakes and moors, heating up the water which dissolves the O2 in the H2O. The gases become less soluble as temperature increases.
Define Molar Concentration (molarity).
the number of moles of solute that can dissolve in 1L of solution.
C=n/v
What does mass/volume percent give?
It gives the mass of solute dissolved in a volume of solutions.
Mass/volumes %=(mass of soluteg/volume of solutionmL)x100%
What does mass/mass percent give?
It gives the mass of a solute divided by the mass of solution.
Mass/mass %=(mass of soluteg/mass of solutiong)x100%
What does volume/volume percent give?
It gives the volume of solute divided by the volume of solution.
Volume/volume %=(volume of solutemL/volume of solutionmL)x100%
What does the Parts per Million and Parts per Billion give?
It usually shows the mass/mass relationships. Both describe the amount of solute that is present in a solution. PPM does not refer to the number of particles, but to the mass of the solute compared with the mass of the solution.
Solubility is measured in…
g/100mL
What is a solution called that has a known concentration?
Standard solution
How many ways are there to prepare an aqueous solution?
Two; dissolve a measured mass of pure solute in a certain volume of solution or dilute a solution of known concentration
How to prepare an aqueous solution by dissolving a measured mass of pure solute in a certain volume of solution?
By using a volumetric flask, you first need to measure the mass of the pure solute, transfer the solute using a funnel, add solvent (usually water) to dissolve solute, continue adding solvent until the bottom of the meniscus appears to touch the line that is etched around the neck of the flask. Standard solutions are never stored in volumetric flasks, instead, are stored in bottle with a secure stopper or cap.
How do you prepare an aqueous solution by diluting a solution of known concentration?
Adding measured amounts of additional solvent to the solution
Note: the number of molecules, moles of solute remains the same before and after the dilution
True or False. Very few compounds are 100% soluble in water.
False.NO compound is 100% soluble in water.
Fill in the blanks. Soluble generally means that more than ____ of solute will dissolve in _____ of water at room temperature. Insoluble generally means that less that _____ per _____ will dissolve.
A)1g
B)100mL
C)0.1g
D)100mL
Why do some ions form soluble compounds, while other ions form insoluble compounds?
Compounds with small charges tend to be soluble and compounds with large charges tend to be insoluble. increasing charge increases the force that holds them together
Compounds with small ions are less soluble and compounds with large ions are more soluble. small ions bond more closely together than large ions, the bond b/w small ions is stronger than the bond b/w large ions with the same charge
True or False. Metal ions are smaller than neutral nucleus and non-metal ions are larger than neutral nucleus.
True.
When you mix two solutions together what two outcomes can occur?
Compounds will remain in solution or a reaction will occur.
How can you tell if a dd rxn has occured?
1) look for ppt
2) look for formation of gas
3) look for formation of water
Hydrogen and alkali metals make hydrides that react with water to produce what?
Gas
Carbonate and acid (carbonic acid) decomposes into what?
Carbon dioxide and water
Sulfide and certain acids make…
…hydrogen sulfide gas
Sodium sulfite and hydrochloric acid yield sulfurous acid which can be broken down into…
…sulfur dioxide gas and water
Is ammonia soluble in water?
Yes, very much so.
When water forms from a dd rxn, what is this known as?
A neutralization rxn, when an acid and a base react.
True or False. Most metal oxides are bases therefore will react with an acid to form an ionic salt and water.
True.
True or False. Non-metal oxides are bases therefore will react with an acid to form an ionic salt and water.
False. Non-metal oxides are acidic therefore will react with a base to form an ionic salt and water.
Fill in the blanks.The ____________________ shows all of the ions present in the two solution, and which ones form the ______________. When writing this equation, you must balance the atoms and the charges.
A) Total ionic equation
B) Precipitate
Fill in the blanks. The ________________ demonstrates only the ions that form the _____________. To show this, you get rid of spectator ions (ions that do _____ take part in the reactionthey appear the same on either side of the equation).
A) Net ionic equaion
B) Precipitate
C) NOT
Qualitative analysis requires…
Repeated steps of precipitate rxns and flame tests to eliminate
Fill in the blanks. __________ is the most abundant substance on Earth’s surface.
WATER
What are the difference between point sources, diffuse source and indirect sources?
Point sources; manufacturing or processing plants that discharges untreated or insufficiently treated waste into a river or lake, spreads pollution over huge areas.
Diffuse sources; pollution from a wide range of sources
Indirect sources; become polluted from indirect sources
True or False. Chlorine is used to kill bacteria and viruses.
True.
Fill in the blank. A process called ____________ removes suspended particles such as clay and microorganisms.
Flocculation
In flocculation, lime and aluminum sulphate are added to yield aluminum hydroxide (a sticky gel that traps the particles). The water is then passed through graded gravel and sand in a filtering tank. Water is often saturated with oxygen by spraying it into the air, which helps remove volatile organic compounds and improves the taste and odour. What happens next?
Chlorine is added again to kill bacteria and ammonia is added to make the chlorine last longer in the piping.
What is the difference b/w hard and soft water?
Hard water is water with high concentrations of calcium, magnesium, iron and sulphate (hard to lather) . While soft water has very low concentrations of these ions (easy to lather).
Explain ion exchange.
Changes in one kind of ion for naother. Hard water passes through a column with beads. When it passes through, water displaces sodium ions in resin.
Fill in the blanks.
Primary treatment; screens remove larger solids, as waste water slowly passes through the _______ tank, smaller particles settle out. In a sedimentation tank, finer sized particles settle out slowly to form ________. Sludge, oils and grease move to sludge digestion tank to be __________________.
Secondary treatment; ____________________ of dissolved organic matter takes place in trickling filter tanks and activated sludge tanks.
Tertiary treatment; Waste water goes to ______________ or used by industries for irrigation.
A) Grit B) Sludge C) Decomposed D) Bacterial decompisiton E) Waterways
