Classification of matter
Ions Ions Ions
Concentration Calculations
Water in the real world
Notes and Errata
100
This is the name for when one substance is dissolved into another substance.
What is a solution?
100
This is the chemical formula for table salt.
What is NaCl? (Sodium chloride; cloruro de sodio)
100
Name one unit we use to measure concentration.
Examples include: percentage by mass, parts per million, and molarity.
100
This is what we mean by the term "water gap."
What is the difference between the water resources of an area and the water that is used by local people?
100
This is the year MFS was founded.
What is 1951?
200
This is the name for a positive ion and a negative ion. (Label them!)
What are: positive ion = cation, negative ion = anion
200
Write the chemical formula and name in Spanish for Magnesium chloride.
What is MgCl2, cloruro de magnesio?
200
Calculate the concentration of 34 g NaCl dissolved in 100 g water in:
-Percentage by mass
-Parts per million
Percentage by mass: ( 34 / 100 )* 100 = 34 %
Parts per million: 34 / 100 = x / 1000000
x = 340,000 ppm
200
When temperature increases, this is what happens to the solubility of gasses.
What is, as temperature increases, LESS gas can be dissolved?
200
This person is the youngest colegio teacher.
Who is Taylor?
300
This is an example of a heterogeneous mixture.
Answers will vary. Any mixture where the components are unevenly distributed works - ranging from non-homogenized milk to a mixed fruit salad.
300
Write the formula and name in English for floruro de hierro (II).
What is: FeF2, Iron (II) fluoride?
300
You want a 250 mL (250 g) aqueous solution of KCl at 22% by mass. How much KCl do you need?
22 / 100 = x / 250
250* 22 = 100*x
x = 5500 / 100 = 55 g KCl
300
This is the word for increasing salt levels in a body of water.
What is salinization?
300
This is the name of the first Costa Rican president.
Who is José Maria Castro Madriz?
400
Name two kinds of pure substances.
What are elements and compounds?
400
Write the formula and name in English and Spanish for two ionic compounds (your choice).
Answers will vary.
400
Is it possible to have a 40% by mass solution of KCl at 50 degrees C? Why or why not?
Yes, this is possible. At 50 degrees C, for every 100 g or water you can have 42 g of solute. This would give a 42% solution by mass when completely saturated. 40% by mass would be unsaturated, which is easy to achieve by mixing less solute into the solvent.
400
This is an explanation of the process of eutrophication.
Should include these steps:
1. Excess nutrients enter a body of water.
2. Algae grow on the surface of the water due to excess nutrients.
3. Oxygen is depleted due to subaquatic vegetation dying off and oxygen levels decreasing.
400
This is the country where Skye was born.
What is Zimbabwe?
500
A substance does not settle out over time. The Tyndall effect is seen when light shines through it. What kind of substance is this?
What is a colloid?
500
Identify the chemical formula and name in English and Spanish for the ionic compound made from Beryllium and Carbon.
What is: Be2C, beryllium carbide, carburo de berilio?
500
Use this graph to explain how you could prepare a supersaturated solution of KNO3. Include specific mass of KNO3 and water and the temperatures at each stage of the process.
Answers will vary. Example: Heat 100 g water to 50 degrees C. Add 85 g KNO3 and dissolve fully. Cool the solution down to 40 degrees. It is now supersaturated.
500
These are three issues from the textbook reading that can impact water quality.
What are pH, heavy metals concentration, gas concentration, ionic compound concentration, and salinity?
500
These are the names of the six people who work in the MFS administration.
Who are: Liza, Ana Xinia, Yuri, Joyce, José Alberto, and Alfredo?