Chemistry Exam :(
What is the electronegativity difference in the compound Aluminum Chloride, AlCl3?
1.55
How many ml of 6.0 M stock do you need to make 250 ml of 2.5 M?
103
C3H8 + 5O2 → 3CO2 + 4H2O If I was given 35 grams of C3H8 how many grams of CO2 would you produce if you had all the Oxygen you wanted.______
105
How many grams are in 1.946 moles of NaCl?
113.7
If you have 2.7 x 1024 atoms of Al how many grams of Al do you have? _____
120
What are the correct coefficients when this equation is balanced? Sb + O2 → Sb4O6
4, 3, 1
Choose all statements below that are part of the Kinetic Molecular Theory. a. Gasses are hard specs that are extremely small. b. Gasses can have some interactions c. Gasses have large amounts of space between them d. Gasses have both elastic and inelastic collisions
a and c
In order to be polar an atom must have the following: a. a large enough electronegativity difference b. be symmetrical c. be unsymmetrical d. be made of a metal and a nonmetal
a and c
What two things must happen for a successful collision? a. orientation b. concentration c. speed d. pressure
a and c
What is the Shape of OF2? You have to draw the Lewis Dot Diagram to get this right.
bent
Which type of chemical reaction would this be classified as: C3H8 + 5O2 → 3CO2 + 4H2O
combustion
Identify the type of chemical reaction demonstrated by this equation: 2KClO3 → 2KCl + 3O2
decomposition
At the same temperature if you increase the volume you...
decrease the pressure
Which type of chemical reaction is this an example of? Fe2(SO4)3 + 6KOH → 3K2SO4 + 2Fe(OH)3
double replacement
When something heats up when it reacts it is an ________thermic reaction When heat has to be added the whole time for the reaction to occur it is an ________ thermic reaction. When you break bonds this action is ________thermic. When you make bonds this action is _______thermic. TEXT ANSWER
exo endo endo exo
A gas with a high molar mass will travel through a small opening faster than a gas with a low molar mass.
false
A single piece of newspaper burns faster than a shredded piece.
false
Adding dissolved solids to liquids lowers the boiling point due to colligative properties.
false
All compounds with polar covalent bonds are polar molecules.
false
An elastic collision is one where two colliding particles both lose some of their kinetic energy.
false
At 50°C temperature and 1.15 atm pressure, water exists in the vapor phase.
false
Electrons in a covalent bond are always shared equally between the two atoms forming the bond.
false
Gases tend to have lower densities than solids because gases have lower molar masses.
false
If the temperature at which a reaction occurs increases, the number of collisions decreases.
false
Intermolecular forces are sometimes greater than intramolecular forces.
false
Linear compounds can never be polar.
false
Orientation of molecules during a reaction does not affect the production of products.
false
Sublimation is going from a gas to a solid.
false
The amount of energy required to change the phase of a molecular substance such as sucrose is greater than an ionic substance such as table salt.
false
The value of Keq is constant over a range of temperatures
false
A reaction is at equilibrium when the rates of the forward and reverse reactions are unequal.
flase
Which is an intermolecular force?
hydrogen bond
A/An _____ is a substance that slows down the rate of a reaction.
inhibitor
Hydrogen bonding is when....
it is a strong attraction between molecules that have hydrogen bonded to either N, O, or F. It is an intermolecular force.
How does a catalyst increase reaction rates?
it lowers activation energy
Which force is the strongest?
network solid
Based on its electronegativity difference, which kind of bond is present in the compound OF2?
polar covalent
If the electronegativity of H is 2.20 and of Cl is 3.55, which type of bond is formed between H and Cl, when they form hydrogen chloride?
polar covalent
Which of the following factors does NOT affect the rate of the reaction of a liquid system?
pressure
Identify the type of reaction shown by this chemical equation: 2Al + 6HCl → 2AlCl3 + 3H2
single replacement
What type of reaction takes place when fluorine reacts with sodium bromide?
single replacement
The reaction below shows an example of which type of reaction? 2Na(s) + Cl2(g) ---> 2NaCl(s)
synthesis
Which types of reactions are essentially opposites of one another?
synthesis and decomposition
In an endothermic reaction, equilibrium shifts _____ when temperature is lowered.
to the left
What is the shape of PF3 ?
trigonal pyramid
Which is defined as the combination of pressure and temperature at which all three states of matter can coexist at equilibrium?
triple point
A mole is defined so that one mole of carbon-12 atoms has a mass of exactly 12 grams.
true
All the gas molecules in this room have roughly the same kinetic energy.
true
If liquid A has more massive molecules than liquid B, liquid A has a higher viscosity.
true
If the atomic mass of a manganese atom is 54.94 amu, then its molar mass is 54.94 g/mol.
true
If two samples of helium and xenon containing the same number of moles at the same temperature are released through an opening at the same time, the helium will travel a longer distance than the xenon.
true
In a balanced chemical equation, the total mass of the reactants is equal to the total mass of the products.
true
Molarity is the number of moles of solute dissolved per liter of solution
true
One mole of a substance has the same number of particles as one mole of any other substance, regardless of what substances are being compared.
true
Temperature is defined as the average kinetic energy of the particles in a sample of matter.
true
The breaking of covalent bonds requires the input of energy.
true
The kinetic molecular theory describes the behavior of matter in terms of particles in motion.
true
The only time energy is released in bonding is when new bonds are formed.
true
The reaction A --- B occurs in a closed system. When the reaction reaches equilibrium at temperature T, the number of molecules changing from A to B is equal to the number of molecules changing from B to A.
true
The stoichiometric relationship between any two substances in a reaction depends on the mole ratio between those substances.
true
When ice melts the ice cubes, not the melted water stay at the same temperature.
true
When you break bonds it always takes energy.
true
What is the probable product of a double-replacement reaction?
two different compounds
Which change in state requires that energy be added to the substance?
vaporizing
Determine the number of moles present in 32.5 g aluminum chloride. (Remember to write the formula first.)
.244
What is the boiling point elevation of a solution containing 17.1 g of sucrose in 100.0 g of water? The molal elevation constant of water is 0.512°C/m and the molar mass of sucrose is 342 g/mol.
.256
How many moles of Ag contain 4.49 × 1023 atoms Ag?
0.745 mol
What are the correct coefficients when this chemical equation is balanced? P4 + O2 → P2O5
1,5,2
At the same temperature, place these phase of matters intermolecular forces in order from weakest to strongest
1. gasses 2. liquids 3. solids
Place the following intermolecular forces in the right order going from strongest to weakest
1. hydrogen 2. dipole-dipole 3.dispersion
What are the correct coefficients when this equation is balanced? K + Br2 → KBr
2,1,2
What is the molality of a solution if it is made up of 35.0 g of NaCl dissolved in 250 grams?
2.4
Determine the mass in grams of 0.0465 mol chromium.
2.42
65.0 grams of NaOH are mixed in 550 ml of water. The molarity of this solution is
2.95
In the compound PCl3, how many total valence electrons are present?
26
There is _______ moles of Phenol are in this solution. 1.32 L 6.01 M
7.5
2C4H10 + 13O2 --------> 8CO2 + 10H2O I must burn ______ grams of C4H10 to produce 15.5 grams of water.
9.9
Which is the product(s) of this reaction? Mg + N2 →
Mg3N2
Which type of reaction takes place in the presence of oxygen and produces carbon dioxide and water?
Combustion
In a chemical equation, (aq) after one of the substances means that it is which of these?
Dissolved in water
Which of the following changes requires an input of thermal energy?
Evaporation
All chemical reactions release energy, although some release it in the form of light and others in the form of heat.
False
Breaking chemical bonds either takes energy or releases energy depending on the which compounds are involved.
False
In a chemical reaction, the products are found on the left side of the arrow.
False
The arrow in a chemical equation means " is equivalent to".
False
The coefficient of each element should be the same on both sides of the equation.
False
Which are the product(s) of this chemical reaction? FeCl3 + 3NH4OH →
Fe(OH)3 + 3NH4Cl
At a fixed volume, as the temperature goes up the pressure goes....
Goes up due to the increase in the number of collisions
According to Le Chatelier's principle, when the pressure is decreased, the equilibrium shifts to the right for only one of the following. For which of the following reversible reactions is this true?
PCl5(g) ----> PCl3(g) + Cl2(g)
Which type of reaction involves one element and one compound reacting?
Single replacement
Which is NOT a sign that a double displacement reaction has occurred?
The coefficients are equal
In the reaction SO2Cl2 ---> SO2+Cl2 heat is evolved. What happens when chlorine (Cl2) is added to the equilibrium mixture at constant volume?
The temperature of the system decreases.
A + B ----> C + D + heat
This is an exothermic reaction
A + B + Heat ----> C + D
This reaction is endothermic
A coefficient tells the lowest whole number ratio of compounds in a given chemical reaction.
True
A precipitate forms when two aqueous solutions react to form a product that cannot dissolve in water.
True
In an aqueous solution, the solute is the part of the solution that is being dissolved in water.
True
What are the products of the double-replacement reaction between aqueous hydrogen bromide and aqueous sodium hydroxide?
Water and sodium bromide
An aqueous solution of magnesium hydroxide is mixed with aqueous copper chloride. Will a visible reaction occur?
Yes, solid copper hydroxide will precipitate out of solution.
What are the products when Zn reacts with HCl? You may pick two or more answers
ZnCl2 H2
