Chapter 2 - Molecules and Solutions Flashcards
What is an electrolyte? /3
A substance that when dissolved in water allows an electrical current to flow through the solution
Types of electrolytes:
- Acids
- Bases
- Salts
Ex. salt, cucumbers, NEURONS, Gatorade
What is a non-electrolyte?
A substance that when dissolved I water doesn’t not conduct electricity
Ex. Sugar
What is electrical conductivity?
A measure of a solution’s ability to allow electric current to flow through
What is an acid? /3
Compounds of Hydrogen and non-metals
Substance that releases H+ (Hydrogen) ions and nonmetal- ion in an aqueous solution
Can be identified with blue litmus paper (blue—>red)
What is a base? /4
Compounds of Hydroxide (OH) and metals
Substance that releases OH- ions and metal+ ions in an aqueous solution
Can be identified with red litmus paper (red—>blue)
Chemical formulas often begin with a metal and ends with OH
What are salts? /3
Compounds of metals and non metals
Substance produced by the chemical bonding of a metallic ion and a nonmetallic ion (other than H+ and OH-)
Can NOT be identified with litmus paper (no effect)
What is pH? /7
Measure that distinguishes acidic/basic/neutral solutions
Universal indicator papers provide a measure of the pH value
A pH scale of 1-14 (usually)
One unit is 10x more acidic/basic from the other
If pH is <7 = acidic (lemon juice)
If pH is = 7 = neutral (water, blood)
If pH is >7 = base (soap)
What is an ion? /5
An atom that becomes electrically charged by losing or gaining an electron
An atom that has become stable by losing/gaining electrons
Gaining electrons = negatively charged
Losing electrons = positively charged
Formation of an ion DOES NOT CHANGE the number of protons or the nature of the element
What is grams per litre? /3
When solute amount is larger
Number of grams of solute per litre of solvent
Formula: C = mass(g)
-————-
volume (L)
What is parts per million? /3
The number of one parts of solute in a million parts of a solvent
Number of milligrams of solute per litre of solution
Formula: C = mass(mg)
——————
volume (L)
What is mass-volume percentage? /2
The number of grams of solute per 100ml of solution
Formula: C = mass(g)
-—————. X100
volume of solution (ml)
What is volume-volume percentage? /2
Number of millilitres of solute per 100ml of solution
Formula: C = volume(ml)
-———————. X100
volume of solution (ml)
What is mass-mass percentage? /2
Number of grams of solute per 100 g of solution
Formula: C = mass (g)
———————. X100
mass of solution (g)
