Chapter 7 – Chemistry Test Questions – Flashcards
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mixture |
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combination of two or more pure substances, both retain identity |
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homogeneous mixture |
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synonym for solution has same composition throughout |
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heterogeneous mixture |
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mixture that does not have same composition throughout |
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colloid |
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homogeneous mixture that contains larger particles |
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will a colloid settle |
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no |
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suspension |
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heterogeneous mixture with larger particles |
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will a suspension settle |
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yes |
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solvent |
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liquid in which anouther substanc eis dissolved |
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solute |
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substance dissolved in a liquid |
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solvation |
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clustering of solvent molecules around a dissolved solutes molecules or ions |
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example of when solvation would happen |
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when salt is dissolved in water |
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hygroscopic |
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having the ability to ull water molecules from the surrounding atmosphere |
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what do we call it when water is the solvent |
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hydration |
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saturated solution |
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solution containing the maximum amoung of solute that will dissolve |
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solubility |
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maximum amount of a substance that will dissolce in a given amountof solvent at a particular temperature |
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miscible |
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mutally soluble in all proportions |
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immiscible |
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opposite of miscible (insolubility) |
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which is clear, a solution or a colloid |
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a solution |
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what is the particle size in a solution |
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less that 2.0 nm |
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what is the particle size in a colloid? |
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between 2.0 and 500 nm |
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what is the particle size in a suspension |
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more than 500 nm |
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air,seawater and gas are all examples of |
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solutions |
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butter, milk and fog are examples of |
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colloid |
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blood and paint are examples of |
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suspension |
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characteristics of a solution |
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transparent, not filterable, does not seperate |
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could a solution be colored |
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yes |
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is a solution filterable |
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no |
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characteristic of colloids |
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murky or opaque, does not seperate |
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is a colloid filterable |
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no |
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characteristics of a suspension |
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murky or opaque, seperates on standing |
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is a suspension filterable |
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yes |
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are gases suspensions, solutions or colloids? |
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solutions |
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moving from a solution to a solid solute is called |
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crystallization |
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moving from a solid solute to a solution is called |
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dissolution |
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does heat generally increase or decrease solubility |
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increase |
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how would you make a supersaturated solution |
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saturate the solution at a higher temperature, then let the solution cool undisturbed |
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after a solution has been supersaturated and cooled, what would a disturbance do to the solution |
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cause it to crystallize |
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is supersaturation a stable state? |
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no |
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the solution process needs similar or compatible |
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intermolecular forces |
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what does "like dissolves like" mean |
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non-polar substances will dissolve in non-polar solutions and polar substances will dissolce in polar substances |
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heat change when dissolving can be |
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positive or negative |
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is dissolving a static process |
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no, there is a lot of back and forth |
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rate of dissolving is dependant on |
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surface area (rock candy vs powdered sugar. |
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what two factors can increase the rate of dissolving |
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heat and stirring |
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how do heat and stirring speed up rate of dissolving |
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by increasing the rate at which molecules collide |
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stirring also increases rate by |
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moving solvaed molecules further from the pure solvent |
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molarity |
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moles of solution over liters solution |
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weight/volume percent |
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mass of solute/volume of solution |
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what are the units for weight/volume percent |
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grams of solute/100 mL solution |
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how would you write weight volume as a conversion factor |
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parts per one hundred (grams over 100 mL) |
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dilution formula |
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m1v1=m2v2 |
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in a dilution formula, what do the variables stand for? |
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m1=concentration of concetrated, v1=volume of concentrated, m2=concentration of diluted, v2= concentration of diluted |
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what units do you need to use when using the dilution equation? |
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it doesn't matter as long as they are the same on both sides |
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Is the volume used in the dilution problem total volume or added volume? |
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total volume |
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what must be used as the common unit when doing stoichiometry equations? |
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moles |
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electrolytes |
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produces ions when dissolved in water adn therefore conducts electricity. |
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what has to happen for a dissolved compound to conduct electricity? |
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the compound must dissociate into ions |
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strong electrolytes |
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dissociates completely in water |
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weak electrolytes |
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partially dissociates in water |
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nonelectrolytes |
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do not dissociate in water |
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colligative particles depend only on |
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the number of particles, not their chemical identity |
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colligative properties (vapor pressure) |
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lowers |
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colligative properties (boiling point) |
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elevation |
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colligative properties (freezing point) |
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depression |
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colligative properties (osmosis) |
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osmosis |
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how do colligative properties lower vapor pressure? |
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the solute makes the liquid less concentrated, therefore fewer particles will be in the vapor phase |
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how do colligative properties elevate boiling points? |
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if the vapor pressure is lower at a particular tamperature, to get the vapor pressure to atmospheric pressure, the temperature must be raised. |
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The boiling point of 1 kg of water is increased by how many degrees celcius for each mole of particles? |
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0.51 degrees celcius |
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How do colligative properties depress the freezing point? |
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if there are contaminants in the liquid (solvent) it is harder for the liquid molecules to form a crysal lattice. |
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the temperature water freezes at is lowered by how many degrees for each mol of particles per 1 kg of water? |
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1.86 degrees |
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is osmosis only (blank) can pass through membrane |
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solvent |
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osmotic pressure |
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the pressure that must be applied to the contaminated solution to half the flow of solvent into that chamber |
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osmolarity is the sum of |
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the molarities for all dissolved particles in a solution |
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osmotic pressure equation |
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osmotic pressure =nMRT |
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what number is used for the constant (R) in the equation for osmotic pressure |
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62.4 L torr/k mol |
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isotonic solution |
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0.30 osmol. Water will not flow in or out of cell, cell stays normal size |
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hypotonic solution |
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less than 0.30 osmol. water flows into the cell, the cell bursts |
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hypertonic solution |
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greater than 0.30 osmol. water flows out of the cell, cell creanates |
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how does dialysis differ from osmosis |
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small particles as well as solvent can diffuse through the semipermeable membrane |