stoichiometry
Use these equations to answer the question:
(0.250 mol Fe/1) (2 mol FeCl3/2 mol Fe) = 0.250 mol FeCl3
(0.353 mol Cl2/1) (2 mol FeCl3/3 mol Cl2) = 2.35 mol FeCl3
Which of the following correctly defines the limiting reactant:
A. The limiting reactant is FeCl3 because you have 0.235 mol produced.
B. The limiting reactant is Fe because you start out with less of it than Cl2
C. The limiting reactant is Cl2 because you produced less product.
D. The limiting reactant is the FeCl3 because that is why you produced from both Fe and Cl2.
C. The limiting reactant is Cl2 because you produced less product.
Which of the following terms best describes the relationship between pressure and temperature?
A. Directly related C. Complimentary
B. indistinctly related D. Inversely related
A. Directly related
What is the opposite of evaporation?
A. Sublimation
B. Condensation
C. Deposition
D. Freezing
B. Condensation
The direct change of a substance from a solid to a gas is called:
A. Boiling
B. Sublimation
C. Condensation
D. Evaporation
B. Sublimation
Blood has a pH of 7.39. It would best be classified as a ___?
A. Base C. Neutral
B. Acid D. Buffer
A. Base, Because even though it is close to 7 the .39 makes it closer to a base than neutral
What is the waste of nuclear fission?
Daughter molecules
What does percent yield show?
It is the percent of the product actually made based on how much product should have been made.
Which of the following values represents absolute zero?
A. -273K C. 273° C
B. 0°C D. 0°K
D. 0°K
The temperature of a 1 g water sample drops by 1°C, resulting in a release of energy from the sample. In which phase will the greatest amount of energy be released?
A. Liquid water at 25°C C. Steam at 100°C
B. Ice at 0°C D. None of these
A. Liquid water at 25°C
The amount of heat required to melt one mole of a solid is called the:
A. Heat of vaporization C. Heating Curve
B. Heat of Fusion D. Cooling Curve
B. Heat of Fusion
A solution containing 1x 103 hydrogen [H+] ions is best classified as ___?
A. Basic
B. Neutral
C. Acidic
C. Acidic because anything from 0-6 is Acidic and the 10^3 means it has 3 [H+] ions therefore it should be classified as an Acidic
If the KeQ of a molecule is > 1, which reaction should be used?
A. Forward reaction C. Neither is preferred
B. Reverse reaction D. French fries work well with Burgers
A. Forward Reaction
A student was working with KCl and O2 to produce KClO3. The student calculated that the amount of KClO3 that needs to be produced is 0.268 moles, but the student only produced 0.200 moles of KClO3. What is the correct way to figure out what the student's percent yield is?
0.200 moles of KClO3/0.268 moles of KClO3 X 100
A balloon is filled with 30L of helium gas at 1.0 atm. What will happen to the volume when the balloon rises to an altitude where the pressure is only 0.25 atm? ( Assume that the temperature and the # of moles remain constant.)
A. The Volume will increase
B. The volume will decrease
C. The volume will stay the same
D. Volume is non-linear and is more like a big ball of wibbly-wobbly, timey-wimey stuff
A. The Volume will increase
1. How much heat will be absorbed by 320g of water when its temperature is raised by 35°C? The specific heat for water is 4.18 J/g°C
Q=47,000J.
Q= (320g) * ( 35°C) * ( 4.18 J/g°C)
Q=47,00J
How Many kilojoules of heat are needed to completely vaporize 42.8 grams of C4H10O at its boiling point? Given △Hvap= 26.5 Kj/mol
A. 74.1 kJ C. 15.3 kJ
B. 9.49 kJ D. 16.3 kJ
C. 15.3 kJ because
The Molar mass is 79g/mol ( 48 + 10 + 16)
42.8g divided by 79g/mol = 0.578mols
0.578mols x 26.5 kJ/mols = 15.3 kJ
What are the products of KOH + H2SO4 -➤
A. SO4K + H3O+ C. KSO4 + H2O
B. K2SO4 + H2O D. KSO4 + H3O +
B. K2SO4 + H2O
21H+ 31H —› 42He + 10N
What type of reaction is this?
A. Fusion
B. Fission
A. Fusion
How many grams of Iron will make 175 grams of Copper?
3CuSO4 + 2Fe -> Fe2(SO4)3 + 3Cu
103g Fe
What volume would 3.00 moles of hydrogen gas occupy at STP?
A. 72.6 L C. 7.47 L
B. 67.2 L D. 22.4 L
B. 67.2 L
Because x= 3(273)(0.0821)
x= 67.2 L
How much heat must be added to .050 kg of aluminum at 25°C to raise its temperature to 125°C? The specific heat of aluminum is 0.90 J/g°C.
4,500J
Q= (50kg)(100°C)(0.90 J/g°C)
Q= 4,500J
Which of the following would likely be an electrolyte in water?
A. C25H52 ( Candle wax) C. C12 H22 O11
B. CaCO3 D. Al ( NO3)3
D. Al(NO3)3
A 5.00 mL sample of H3PO4 is titrated with 7.12 mL of a .1090 M NaOH solution. What is the concentration of the H3PO4 solution?
H3PO4 + 3NaOH ➤ 3H2O + Na3PO4
0.052 M
Because .1090 = x/0.00712
x= 0.000776
0.000776/1 x 1/3 = 0.000259
X= 0.000259/0.005 = 0.052 M H3PO4
M= 0.052
If an object has 6.25% of its original 14C molecules left, how many half-lives has it gone through?
4 Half-lives