TEAS 7 - Science (Solutions and Chemical Reactions) Flashcards
Water is known as the universal ___.
solvent
In chemistry, opposites ___.
attract
Water is a universal solvent because of its unique ___, where one side has a positive charge and the other side has a negative charge.
polarity
The positive ends of water will attract the ___ ends of other molecules and the negative end of water will attract ___ ends of other molecules.
negative
positive
Within a water molecule, the bond between the hydrogen atom and oxygen atom is known as a ___ bond. However, the bond between the hydrogen atom of one water molecule and the oxygen atom of another water molecule is called a ___ bond.
covalent
hydrogen
What allows water molecules to bind together?
hydrogen bonds
What gives water its high surface tension?
hydrogen bonds
___ refers to the maximum amount of a substance that can dissolve in a given amount of solvent at a specific temperature.
Solubility
What is the unit for concentration?
molarity
Molarity is a unit that shows how ___ a solution is.
concentrated
What is the Molarity of a solution with 45 moles dissolved in 0.50 L of water?
M = mols/L
M = 45 mols/ 0.05L
M = 90 M
What would be the Molarity of a solution with 100.0 moles of Kool-Aid powder dissolved in 450.0 mL of water?
M = mols/L
mols = 100.0
L = 450 mL = 0.450 L
M = 100 mols/ 0.450 L
M= 222 M
Gabby has a 0.500 L of a 2.5 M solution of Copper Sulfate. She wants a 1.25 M solution. Describe how she could do this by just adding water.
M1V1 = M2V2
M1 = 2.5M
V1 = 0.500L
M2 = 1.25 M
V2 = ?
(2.5M)(0.500L) = (1.25M)(V2)
V2 = [(2.5M)(0.500L)] / 1.25M
V2 = 1.00L
What is teh unit of molarity?
moles/Liter
Balance the following chemical equation:
CH4 + Cl2 → CCl4 + HCl
CH4 + 4 Cl2 → CCl4 + 4 HCl
*CH4 + Cl2 → CCl4 + HCl
C: 1 C: 1
H: 4 H: 1
Cl: 2 Cl: 5
CH4 + Cl2 → CCl4 + 4 HCl
C: 1 C: 1
H: 4 H: 4
Cl: 2 Cl: 8
CH4 + 4 Cl2 → CCl4 + 4 HCl
C: 1 C: 1
H: 4 H: 4
Cl: 8 Cl: 8
Which type of chemical reaction is demonstrated by the reaction below?
Ba(NO3)2 + Na2SO4 → BaSO4 + 2 NaNO3
Double replacement
*In a double replacement reaction, two metal ions (Ba²+ and Na+) switch places with each other in two ionic compounds
Which of the following compounds contains ionic bonds?
NaBr
In a redox reaction, oxidation is the _______ of electrons and reduction is the _______ of electrons.
loss; gain
What is the “memory trick” for oxidation and reduction?
“OIL RIG,” which stands for “Oxidation Is Loss (of electrons)” and “Reduction Is Gain (of electrons)”
it means that when a substance loses electrons, it is oxidized, and when it gains electrons, it is reduced.
Which of these statements is true about pH?
- higher pH values would have a lower [H+]
- lower pH values would have a higher [H+]
- A pH of 6 is more acidic than a pH of 8
The same single-replacement reaction is run in two different beakers. The beakers are labeled as Beaker A and B and are heated to 75oC and 100oC, respectively. If the reactions are run for 15 minutes each, which of the following results would you expect to observe?
Beaker B produces more product than Beaker A
*As the temperature of a reaction increases, the reaction rate increases as well. This is due to an increased number of collisions that occur between molecules during a reaction. Since Beaker B is at a higher temperature, it should produce more product than Beaker A since the reaction times are equal.
Balance the following chemical equation:
C3H8 + O2 → CO2 + H2O
C3H8 + 5 O2 → 3 CO2 + 4 H2O
*C3H8 + O2 → CO2 + H2O
C: 3 C: 1
H: 8 H: 2
O: 2 O: 3
C3H8 + O2 → 3 CO2 + H2O
C: 3 C: 3
H: 8 H: 2
O: 2 O: 7
C3H8 + O2 → 3 CO2 + 4 H2O
C: 3 C: 3
H: 8 H: 8
O: 2 O: 10
C3H8 + 5 O2 → 3 CO2 + 4 H2O
C: 3 C: 3
H: 8 H: 8
O: 10 O: 10
Br2 is classified as which of the following?
Molecule
*Br2 is classified as a molecule because it is composed of two atoms of the element, Br.
Molecules are substances that are composed of two or more atoms.
Compounds are substances that are composed of two or more different types of atoms (H2O is an example since it contains both H and O).
An element is a substance whose atoms all have the same number of protons (same chemical identity), and Br2 is the elemental form of bromine.
An ion is a charged atom or molecule and will contain a (+) or (-).
Predict the missing product of the following reaction:
Zn + 2AgNO3 → 2Ag + _________
Zinc nitrate
*The reaction above is an example of a single replacement reaction, where one metal ion replaces another in an ionic compound. The starting compounds are zinc (Zn) and silver nitrate (AgNO3). Zn replaces Ag in AgNO3 to form Zn(NO3)2. Although similar, zinc nitrite has the formula Zn(NO2)2.