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WorksheetsCHEMISTRY REVIEW
Total questions: 70
Worksheet time: 35mins
A student observes that a certain metal rusts quickly when left outdoors. Which of the following is the BEST scientific question the student could ask based on this observation?
Why is metal useful?
What are the different types of metal?
What factors affect how quickly this metal rusts?
Is rust a dangerous substance?
A science textbook states that increasing the temperature of a reaction generally increases the rate of the reaction. To define a problem based on this information, a student might ask:
What is the fastest reaction?
How does temperature affect the rate of this specific reaction?
Are all reactions affected by temperature?
What are the products of this reaction?
A scientist uses a ball-and-stick model to represent a methane molecule (CH4). What is the primary purpose of this model?
To show the color of each atom in the molecule.
To accurately depict the size of the molecule.
To illustrate the arrangement of atoms and bonds within the molecule.
To show the movement of electrons in the molecule.
A flowchart is used to represent the steps in a chemical reaction mechanism. This flowchart serves as a:
Physical model.
Mathematical model.
Conceptual model.
Computational model.
A student performs an experiment multiple times and obtains the following measurements for the density of a substance: 2.71 g/mL, 2.69 g/mL, 2.72 g/mL, and 2.55 g/mL. The value 2.55 g/mL appears to be:
A precise measurement.
An accurate measurement.
An outlier, possibly due to error.
The average density.
A graph shows that as the concentration of a reactant increases, the rate of the reaction also increases. This represents a:
Source of error.
Statistical feature.
Pattern in the data.
Limitation of the experiment.
A student collects data on the mass and volume of several aluminum samples. To determine the density of aluminum, the student should:
Add all the mass values together.
Subtract the smallest volume from the largest volume.
Divide the total mass by the total volume.
Divide the mass of each sample by its corresponding volume and then calculate the average.
A solution has a concentration of 2.0 M and a volume of 0.5 L. The number of moles of solute in the solution is:
0.25 moles
1.0 mole
2.5 moles
4.0 moles
Experimental data shows that increasing the concentration of an enzyme increases the rate of a biochemical reaction up to a certain point. This observation is best explained by the scientific idea that:
Enzymes are consumed in the reaction.
Enzymes provide an alternative reaction pathway with lower activation energy.
Increasing concentration always increases reaction rates indefinitely.
The shape of the enzyme's active site is unaffected by substrate concentration.
A model of gas behavior shows that gas particles are in constant, random motion. This model helps explain the phenomenon of diffusion because:
It shows that gas particles have no mass.
It illustrates how particles spread out from an area of high concentration to low concentration through their random movement.
It demonstrates that gas particles attract each other.
It proves that gases are less dense than liquids.
Based on the principle of conservation of mass, in a chemical reaction:
The total number of molecules remains constant.
The total volume of the reactants equals the total volume of the products.
The total mass of the reactants equals the total mass of the products.
The number of moles of reactants equals the number of moles of products.
A student observes that when a solid substance is heated, it eventually melts into a liquid. Using the kinetic molecular theory, which statement best explains this observation, linking the increase in temperature to the behavior of the particles in the solid and liquid states?
The particles in the solid move slower as temperature increases, causing the solid to melt.
The particles in the solid gain energy and move more freely as temperature increases, leading to melting.
The particles in the liquid lose energy and become more ordered as temperature increases.
The particles in the solid lose energy and become fixed in place as temperature increases.
Which of Dalton's Postulates was later modified due to the discovery of isotopes?
All matter is made of atoms.
Atoms of a given element are identical in mass and properties.
Compounds are formed by a combination of two or more different kinds of atoms.
A chemical reaction is a rearrangement of atoms.
Thomson's cathode ray tube experiment led to the discovery of the:
Nucleus.
Proton.
Electron.
Neutron.
Rutherford's gold foil experiment provided evidence for:
The existence of neutrons in the nucleus.
The quantization of electron energy levels.
A dense, positively charged nucleus at the center of the atom.
The wave-particle duality of electrons.
Bohr's model of the atom introduced the idea that electrons:
Move randomly within the atom.
Orbit the nucleus in specific energy levels.
Are negatively charged particles embedded in a positive matrix.
Can be found with both precise momentum and position simultaneously.
The Heisenberg Uncertainty Principle states that it is impossible to know simultaneously with high precision the:
Mass and charge of an electron.
Position and velocity (or momentum) of an electron.
Number of protons and neutrons in an atom.
Energy and size of an atom.
The Rutherford model of the atom differed from the earlier "plum pudding" model proposed by Thomson in that:
It described the atom as a solid sphere.
It proposed that electrons were embedded in a positively charged sphere.
It suggested that atoms have a small, dense nucleus with electrons orbiting around it.
It stated that atoms are indivisible.
Which subatomic particle has a positive charge and is located in the nucleus of an atom?
Electron
Proton
Neutron
Ion
Neutrons are located in the ______ of an atom and have a ______ charge.
Nucleus, neutral
Shell, positive
Orbit, negative
Nucleus, positive
Compared to protons, electrons have:
A much larger mass and the same charge.
A much smaller mass and the opposite charge.
Approximately the same mass and the same charge.
Approximately the same mass and the opposite charge.
An ion is formed when an atom:
Changes the number of protons in its nucleus.
Changes the number of neutrons in its nucleus.
Gains or loses electrons.
Undergoes radioactive decay.
Objective 6E: Construct models to express the arrangement of electrons in atoms of representative elements using electron configurations and Lewis dot structures. (Found in Unit 1 in Your Journal) 23. The electron configuration of nitrogen (atomic number 7) is:
1s2 2s2 2p1
1s2 2s2 2p2
1s2 2s2 2p3
1s2 2s2 2p4
The number of valence electrons in an atom of oxygen is:
6
4
2
8
The Lewis dot structure for a chlorine atom (Cl) shows:
Cl with 6 dots around it.
Cl with 7 dots around it.
Cl with 8 dots around it.
Cl with 1 dot around it.
The correct chemical formula for magnesium chloride is:
MgCl
MgCl₂
Mg₂Cl
Mg₂Cl₃
The correct IUPAC name for the compound N₂O₅ is:
Nitrogen oxide
Dinitrogen pentoxide
Nitrogen(V) oxide
Nitrogen pentoxide
The correct IUPAC name for the ionic compound FeCl₃ is:
Iron chloride
Iron(III) chloride
Iron trichloride
Monoiron trichloride
The chemical formula for sulfur trioxide is:
SO₂
S₃O
SO₃
S₂O₃
According to VSEPR theory, the molecular geometry of BeCl₂ is:
Bent
Linear
Trigonal planar
Tetrahedral
The molecular geometry of NH₃ is trigonal pyramidal. This is because the central nitrogen atom has:
Three bonding pairs and zero lone pairs of electrons.
Three bonding pairs and one lone pair of electrons.
Four bonding pairs and zero lone pairs of electrons.
Two bonding pairs and two lone pairs of electrons.
A molecule with a central atom surrounded by three bonding pairs of electrons and no lone pairs will have a ______ molecular geometry.
Bent
Trigonal pyramidal
Trigonal planar
Tetrahedral
The molecular geometry of CH₄ is tetrahedral. The bond angles in this molecule are approximately:
90 degrees
109.5 degrees
120 degrees
180 degrees
Ionic compounds typically have high melting and boiling points due to:
Weak intermolecular forces.
Strong intramolecular forces (ionic bonds).
The presence of delocalized electrons.
Weak intramolecular forces (covalent bonds).
Covalent compounds generally have lower melting and boiling points compared to ionic compounds because:
They have strong intramolecular forces.
They have strong intermolecular forces.
Their intermolecular forces are generally weaker than ionic bonds.
They conduct electricity well in the solid state.
Metallic substances are good conductors of electricity due to the presence of:
Strong covalent bonds.
Strong ionic bonds.
Delocalized electrons that can move freely.
Strong intermolecular forces.
Which type of substance is likely to be brittle and non-conductive as a solid?
Ionic compound
Covalent network solid
Metallic solid
Molecular solid
A mole is defined as:
The mass of one atom of carbon-12.
The volume occupied by one gram of a substance.
The amount of a substance that contains as many elementary entities as there are atoms in exactly 12 grams of carbon-12.
The number of grams of a substance that contains one atom
The molar mass of water (H₂O) is approximately:
16 g/mol
17 g/mol
18 g/mol
19 g/mol
How many moles are there in 48 grams of oxygen gas (O₂)? (Molar mass of O₂ = 32 g/mol)
0.5 moles
1.0 mole
1.5 moles
2.0 moles
What is the mass in grams of 0.25 moles of glucose (C₆H₁₂O₆)? (Molar mass of C₆H₁₂O₆ = 180 g/mol)
4.5 grams
45 grams
720 grams
0.0014 grams
Objective 8B: Calculate the number of atoms or molecules in a sample of material using Avogadro's number (Found in Unit 6 in Your Journal) 42. Avogadro's number is approximately equal to:
6.022×10²²
1.661×10⁻²⁴
6.022×10²³
3.011×10²³
How many molecules are present in 1 mole of carbon dioxide (CO₂)?
1
2
6.022×10²³
12.044×10²³
How many atoms are present in 2 moles of helium (He)?
3.011×10²³
6.022×10²³
1.2044×10²⁴
2
A sample of water (H2O) contains 1.8066×10^24 molecules. How many moles of water are in this sample?
1 mole
2 moles
3 moles
0.5 moles
Interpret, write, and balance chemical equations, including synthesis, decomposition, single replacement, double replacement, and combustion reactions using the law of conservation of mass (Found in Unit 5 of Your Journal) Which of the following equations is balanced correctly?
H2 +O2→H2O
2H2+O2 →2H2O
H2+2O2 →2H2O
2H2+2O2→2H2O
The following equation represents a ______ reaction: 2H2O→2H2+O2
Synthesis
Decomposition
Single replacement
Combustion
In the reaction Zn+2HCl→ZnCl2+H2, what type of reaction is taking place?
Synthesis
Decomposition
Single replacement
Double replacement
Differentiate among acid-base reactions, precipitation reactions, and oxidation-reduction reactions. Which of the following is a characteristic of an acid-base reaction?
Formation of a solid precipitate
Transfer of electrons
Formation of water
Release of oxygen gas
Differentiate among acid-base reactions, precipitation reactions, and oxidation-reduction reactions. (Found in Unit 5 of Your Journal) A reaction that produces a solid when two aqueous solutions are mixed is called a:
Acid-base reaction
Precipitation reaction
Oxidation-reduction reaction
Combustion reaction
In the reaction 2H₂+O₂ →2H₂O, how many moles of water are produced from 1 mole of O₂?
1 mole
2 moles
3 moles
4 moles
Given the reaction N₂(g) + 3H₂ (g)→2NH₃ (g), how many liters of NH₃ can be produced from 5 liters of N₂ (assuming constant temperature and pressure)?
2.5 L
5 L
10 L
15 L
Which of the following is a postulate of the kinetic molecular theory?
Gas particles have significant volume.
Gas particles are in constant, random motion.
There are strong attractive forces between gas particles.
The average kinetic energy of gas particles is independent of temperature.
According to the kinetic molecular theory, gas particles:
Move slowly and in an orderly fashion.
Are held together by strong forces.
Have negligible volume compared to the volume of the container.
Lose energy with each collision.
The average kinetic energy of gas particles is directly proportional to:
Pressure
Volume
Temperature
Number of moles
Which of the following statements about ideal gases is TRUE, according to Kinetic Molecular Theory?
Gas particles attract each other
Gas particles have a significant volume
Gas particles move randomly
Energy is lost when gas particles collide
Boyle's Law states that at constant temperature, the pressure of a gas is inversely proportional to its:
Number of moles
Volume
Temperature
Density
Charles's Law states that at constant pressure, the volume of a gas is directly proportional to its:
Number of moles
Pressure
Temperature
Density
Describe and calculate the relationships among volume, pressure, number of moles, and temperature for an ideal gas (Found in Unit 7 in your Journal) The Ideal Gas Law is represented by the equation:
PV=nRT
P1V1 =P2V2
T1/V1=T2/V2
P1V1T1=P2V2T2
A solution that conducts electricity is classified as a(n):
Non-electrolyte
Electrolyte
Saturated solution
Supersaturated solution
Which of the following is a strong electrolyte in solution?
Sugar
Ethanol
Sodium chloride
Pure water
A solution that contains the maximum amount of solute that can dissolve at a given temperature is:
Unsaturated
Saturated
Supersaturated
Dilute
A solution that contains more solute than it can theoretically hold at a given temperature is:
Unsaturated
Saturated
Supersaturated
Dilute
According to a solubility curve, the solubility of most solids in water:
Increases with increasing temperature.
Decreases with increasing temperature.
Is unaffected by temperature.
Increases with decreasing temperature.
The solubility of gases in liquids generally ______ with increasing temperature.
Increases
Decreases
Remains constant
Fluctuates
Which of the following factors increases the rate of dissolution of a solid in a liquid?
Decreasing temperature
Decreasing surface area
Agitation (stirring)
Using larger solute particles
How does increasing the surface area of a solute affect the rate of dissolving?
Increases the rate
Decreases the rate
Does not affect the rate
Depends on the solute
Which of the following compounds is generally soluble in water?
AgCl
PbSO4
NaNO3
CaCO3
In the double replacement reaction Pb(NO3)2 (aq)+2KI(aq)→PbI2 (s)+2KNO3 (aq), which product is the precipitate?
Pb(NO3)2
KI
PbI2
KNO3
According to general solubility rules, most chloride salts are soluble in water. Which of the following chloride salts is an exception and insoluble?
NaCl
KCl
CaCl₂
AgCl
