Physical Science Semester 1 Final Exam
Consider the given equation: Balance the equation and calculate how many moles of HNO3 are produced from 1.8 g of Pb(NO3)2
0.011
Under standard temperature and pressure, magnesium reacts with hydrochloric acid to produce magnesium chloride and hydrogen. Mg + 2 HCl --> MgCl2 + H2 If 2.24L of hydrogen gas is produced, the moles of magnesium used in the reaction is _____.
0.10
How much of a 16 M stock solution must you add to make 4 L of a 1 M diluted solution?
0.25 L
You conduct an experiment that requires the creation of an ammonia solution. You do this by reacting 50.0 L of nitrogen gas with excess hydrogen gas at STP to create ammonia gas using the Haber process given by the following reaction: N2 (g) + 3H2 (g) → 2NH3 (g). Assuming the reaction had 100% yield, you then bubble the ammonia into water to make 5.0 L of solution. What is the molarity of the resulting ammonia solution?
0.89 M
What volume would you need to dilute 0.2 L of a 15 M solution to obtain a 3 M solution?
1 L
Calculate the amount, in g, of Copper Sulphate produced when 10g of Copper Oxide is reacted with 20ml of 0.5M of Sulphuric acid. CuO + H2SO4 --> CuSO4 + H2O
1.60
If 1.605 kg of mercury are used in the reaction 2Hg + O2 → 2HgO, what is the mass of HgO, in kilograms, that are produced? (The molar mass of Hg = 200.59 g/mol, and the molar mass of HgO = 216.59 g/mol.)
1.733 kg HgO
If the percentage yield for the reaction below is 28.5%, calculate the amount of bromine produced from 42g of CBr4. CBr4 + O2 --> CO2 + 2Br2
11.53
How many moles of Na are needed to produce 15 moles of NaCl in the reaction 2Na + Cl2 → 2NaCl?
15
How many valence electrons are in a carbon dioxide (CO2) molecule?
16
At STP, how much space (in liters) will 0.750 moles of argon gas occupy?
16.8 L
Choose the correctly balanced equation for the following reaction: Potassium + water → potassium hydroxide + hydrogen gas
2K + 2H2O → 2KOH + H2
Under standard temperature and pressure (stp), when ammonia gas is bubbled into 30mL of water, a solution of ammonium hydroxide of 5M is produced. NH3 + H2O --> NH4OH Calculate the volume, in L, of NH3 gas used.
3.36
When the equation below is balanced and all coefficients are reduced to lowest whole number, what is the sum of all coefficients? HI + KMnO4 + H2SO4 --> I2 + MnSO4 + K2SO4 + H2O
31
How many valence electrons does silicon have?
4
_____ valence electrons are present in a neutral silicon (Group 14) atom.
4
A hydrocarbon CxHy burns in full supply of oxygen to produce carbon dioxide and water. Which of the following correctly represents the balanced equation for the above reaction?
4 CxHy + (4x+y) O2 --> 4x CO2 + 2y H2O
How many millilitres of 0.200M NaOH are needed to react with 15mL of 0.400M H2SO4 solution? 2NaOH + H2SO4 --> Na2SO4 + 2H2O
60
In a reaction, 12g of CO reacts with excess of O2 to produce 12g of CO2. The unbalanced reaction between CO and O2 is given below: CO + O2 --> CO2 Calculate the percentage yield for the reaction.
63.6%
Determine the percent yield if the theoretical yield is 20 g and the actual yield is 15 g.
75%
How many dots should be around an elemental symbol in a Lewis dot diagram if it has a full octet?
8
How many total dots should the diagram for silicon tetrahydride, SiH4 include?
8
How many valence electrons does krypton have?
8
Select the most suitable definition for stoichiometry.
A branch of chemistry that shows the ratio relationship between substances in chemical reactions.
What is a nonbonding electron domain?
A lone pair of electrons
What is the octet rule?
A rule that says atoms like to have full valence shells of eight electrons.
Which of the following statements best describes a supersaturated solution?
A solution that contains more than the maximum amount of dissolved solute than a saturated solution under the same conditions.
What is a coefficient?
A whole number that appears in front of a compound or element in a balanced chemical equation.
Using the solubility table, which of these salts would you predict to be insoluble in water?
AgCl
Which of the following groups of atoms will easily give up outer electrons?
Alkaline earth metals
Which of the following is NOT true regarding solubility curves?
All substances increase in solubility with temperature.
Which of the following elements is a main group element?
Aluminum
What is the difference between a hydrate and an anhydrate?
An anhydrate is a hydrate with the water removed.
What creates polarity?
An unequal pairing of electrons
What is meant by the term molar volume?
At STP, one mole of any gas occupies 22.4 liters.
Which of these elements has the largest atomic radius?
Barium (Ba)
All alkaline earth metals have two electrons in their outer s subshell. The energy required to remove the valence electron from each alkali earth metal is different. In which case is the energy lowest?
Barium, Ba
Why do some molecules have resonance?
Because electrons are mobile and will move to different positions within a molecule if they can.
How is solubility determined?
By determining the maximum mass of a solute that can be dissolved in 100 g of a solvent at a given temperature.
A hydrocarbon is a compound that contains the elements carbon and hydrogen only. If a sample of gaseous hydrocarbon is found to contain 82.8% carbon, calculate the empirical formula of the hydrocarbon.
C2H5
Which of the following could be an empirical formula?
CH
Of the following choices, which has the highest ionization energy?
Chlorine, Cl
In the Periodic Table, if you move from element Lithium (Li) to element Potassium (K), the ionization energy will:
Decrease
In chemistry, the Greek letter delta:
Designates partial charges
If a polyatomic ionic compound has gained two hydrogen ions, such as H2 PO4-. How does its name begin?
Dihydrogen
What type of intermolecular force exists between polar molecules?
Dipole-dipole
Which of the following is the poorest conductor of electricity?
Fluorine (F)
Metalloids have both metallic and non-metallic properties. A few metalloids are found within:
Group 14 and Group 15
Consider the reaction: 2KMnO4 +5Hg2Cl2 + 16HCl --> 10HgCl2 + 2MnCl2 + 2KCl + 8H2O If 2g of KMnO4, 8g of Hg2Cl2 and 10g of HCl are used in the reaction, which of the following is the limiting reagent?
Hg2Cl2
Which of the following statements is true? I. In an ionic bond, electrons move toward the atom that is more electronegative. II. A cation is a negatively charged atom. III. A positively charged atom is called an anion. IV. Under biological conditions, ionic bonds are stronger than covalent bonds.
I
If a carbon atom has four valence electrons, which of the following statements are TRUE? I. Carbon can form a triple covalent bond with another carbon atom. II. A carbon atom CANNOT form two double bonds simultaneously. III. A carbon atom can form four single covalent bonds simultaneously.
I and III
Hydrogen bonds occur between hydrogen in one polar molecule and _____ in another polar molecule. I. Oxygen II. Fluorine III. Nitrogen
I, II, and III
Increase in atomic radii down a group, that is from top to bottom, in the periodic table is due to:
Increased number of energy shells
Which of the following describes molecules with the same chemical formula but different molecular structures?
Isomer
As you move from left to right on the periodic table, what generally happens to the boiling point of elements?
It increases, then decreases.
As you move from left to right on the periodic table, what happens to the electronegativity?
It increases.
As you move from top to bottom on the periodic table, what generally happens to the metallic character of elements?
It increases.
What is the dilution of solutions equation?
M1 V1 = M2 V2
What is the correct name for MgCl2?
Magnesium chloride
Which element is a transition group metal and likely to exist in many different forms?
Manganese
Which of the following calculations is NOT part of determining the empirical formula?
Moles to mass
What monomer are carbohydrates made of?
Monosaccharides
Which of the following best describes the relationship between electronegativity and ionization energy of atoms across a periodic table?
Moving from top to bottom, both electronegativity and ionization energy decrease.
Which of the following relationships between the size of the anionic or cationic radii and the corresponding atomic radii is correct?
Na+ < Na
Which of the following is an example of an ionic compound?
NaCl
Which of these elements has the smallest atomic radius?
Nitrogen (N)
If carbon, electronegativity of 2.6 were to make a chemical bond with sulfur, electronegativity 2.6, what kind of bond would it form?
Non-polar covalent
Two atoms with the same electronegativity would form what kind of bond?
Nonpolar covalent
How is percent yield calculated?
Percent yield = actual yield/theoretical yield x 100
Which of the following will react violently with water to form a base?
Potassium (K)
If the first ionization energy is the energy it takes to remove one electron from an atom, the second ionization energy is the amount of energy it takes to remove a second electron from that same atom. Which of the following explains why the second ionization energy of a particular element will usually be greater than the first ionization energy?
Removing one electron creates a positive ion, which results in a stronger attraction between the second electron and the nucleus
In a reaction at standard temperature and pressure, 30g of sulfur reacts with 2L of oxygen gas according to the balanced equation S + O2 --> SO2 Which of the following statements is correct?
Sulfur is in excess by 0.846 mole.
What is the definition of solubility?
The ability of a solute to dissolve in a solvent
Which family has the lowest electronegativity?
The alkali metals
Why are the transition metals able to show different properties like varying color and paramagnetism?
The d orbitals are unfilled
What does the empirical formula show?
The kind and proportions of atoms in a substance in its simplest form.
What is the electron sea model?
The model of metallic bonding where electrons float free in a sea of electrons around metal atoms.
When naming a binary covalent compound, what determines the prefix for an element in the compound?
The number of atoms of that element in the compound.
In the formula MgSO4 nH2 O, what does the n before the H2 O stand for?
The number of moles of water.
What happens in constructive interference?
The orbitals add.
Which of the following best describes the octet rule?
The outermost energy shell of an atom likes to be full with eight electrons.
What is an excess reactant?
The reactant that doesn't get used up as a reactant and is left over
What is a London dispersion force?
The weak intermolecular force that results from the motion of electrons that creates temporary dipoles in molecules.
Why are metals good conductors of electricity?
Their outer electrons are held very loosely.
How is an ionic bond formed?
Through the transfer of electrons
What is the shape of a Boron Trifluoride molecule, BF3?
Trigonal planar
What is the universal solvent?
Water
When does an alkane not follow the saturation formula, 2N + 2 rule, for the number of hydrogen atoms?
When the alkane is arranged in a ring.
What causes a dipole?
When the electrons are concentrated more at one end of a molecule, that end is slightly negative, and the other end, where the electrons aren't as concentrated, is slightly positive.
Hydrogen bonds exist between molecules X and Y. Which of the following combinations could be X and Y?
X is water, H2 O Y is ammonia, NH3
If 2.5 moles of zinc react with 6.0 moles of hydrochloric acid in the equation Zn + 2HCl → ZnCl2 + H2, what is the limiting reactant?
Zn
Electronegativity is the ability of an atom to _____
attract electrons.
Transition metals are found between the second and third group of the periodic table and are described as elements with a partially filled _____ orbital.
d
Which of the elements below has the smallest ionization energy?
francium (Fr)
An organic compound is represented by RX. Identify X.
halogen
As you move from left to right on the periodic table, what generally happens to the ionization energy?
it increases
A common feature of main group elements is that their electron configurations end in either _____ or _____ orbitals.
s;p
Oxygen (O) has a _____ atomic radius than Magnesium (Mg), a _____ ionization energy than Neon (Ne), and a _____ electronegativity than Lithium (Li).
smaller; smaller; greater
The starting point of a stoichiometric problem is _____.
the balanced equation
A sigma bond occurs when _____.
two orbitals directly overlap but there is only one bonding interaction
