WGU D425 MASTER REVIEW 2026/2027 | INTRO TO CHEMISTRY
COMPLETE OA EXAM PREPARATION | MOST TESTED TOPICS |
HIGH-YIELD Q&A | VERIFIED ANSWERS
1. If you were to add a powdered drink mix to the iced carbonated water, how
would the classification of the mixture change, if at all?
It may become a homogeneous mixture.
It will become an element.
It will become a compound.
It will remain a heterogeneous mixture.
2. What type of property is weight classified as in chemistry?
Extensive
Chemical
Intensive
Physical
3. What is the ideal gas constant R used in the calculation of gas volume?
0.08205 L*atm/ mol*K
8.314 J/mol*K
0.0821 L*atm/ mol*K
62.36 L*torr/mol*K
4. The limiting reactant of a reaction can be used to calculate the...
Experimental yield
Both A. and C.
, Actual yield
Theoretical yield
5. Describe the process that occurs during a decomposition reaction using the
provided equation as an example.
In a decomposition reaction, a compound breaks down into simpler
substances, as seen when Fe(OH)3 breaks down into Fe2O3 and
H2O.
In a decomposition reaction, elements combine to form a compound.
In a decomposition reaction, two compounds react to form a single
product.
In a decomposition reaction, ions exchange partners to form new
compounds.
6. A substance has a melting point of -7°C and a boiling point of 59°C. What is
its state at room temperature (20°C)?
Solid
Gas
Liquid
7. Mass, volume, and the amount of energy in a substance are ___________
properties
chemical
extensive
physical
intensive
,8. In a laboratory experiment, if the temperature of the system containing H2(g)
and F2(g) is raised significantly, what would you expect to observe in terms of
reactant and product concentrations?
The concentrations of both reactants and products will remain
unchanged.
The concentration of products will increase while the concentration of
reactants will decrease.
The reaction will stop completely and no changes will occur.
The concentration of reactants will increase while the concentration
of products will decrease.
9. If SnCl2 is dissolved in water, what type of ions would you expect to form in
solution, and how would this affect the solution's conductivity?
You would expect to form only neutral molecules, which would not
affect conductivity.
You would expect to form Sn^2+ and Cl^- ions, which would increase
the solution's conductivity.
You would expect to form Cl2 gas, which would increase the solution's
conductivity.
You would expect to form Sn^2+ ions only, which would decrease
conductivity.
10. Describe how the average atomic mass of an element is calculated using its
isotopes and their relative abundances.
The average atomic mass is determined by the number of protons in
the nucleus.
The average atomic mass is the sum of all isotopes' masses without
considering their abundances.
, The average atomic mass is simply the mass of the most abundant
isotope.
The average atomic mass is calculated by multiplying the atomic
mass of each isotope by its relative abundance and then summing
these values.
11. What is the formula used to convert molecules to moles?
Number of moles = Number of molecules / Avogadro's number
Number of moles = Number of molecules - Avogadro's number
Number of moles = Number of molecules + Avogadro's number
Number of moles = Number of molecules x Avogadro's number
12. What is the formula of the ioinic compound formed when ions of calcium
and nitrogen combine?
Ca3N2
Ca2N
CaN2
Ca2N3
CaN
13. What is the pH of a solution if it has [OH-] =2.52x10-2 M? Is it acidic or basic?
1.60; acidic
12.4; basic
12.4; acidic
1.60; basic
COMPLETE OA EXAM PREPARATION | MOST TESTED TOPICS |
HIGH-YIELD Q&A | VERIFIED ANSWERS
1. If you were to add a powdered drink mix to the iced carbonated water, how
would the classification of the mixture change, if at all?
It may become a homogeneous mixture.
It will become an element.
It will become a compound.
It will remain a heterogeneous mixture.
2. What type of property is weight classified as in chemistry?
Extensive
Chemical
Intensive
Physical
3. What is the ideal gas constant R used in the calculation of gas volume?
0.08205 L*atm/ mol*K
8.314 J/mol*K
0.0821 L*atm/ mol*K
62.36 L*torr/mol*K
4. The limiting reactant of a reaction can be used to calculate the...
Experimental yield
Both A. and C.
, Actual yield
Theoretical yield
5. Describe the process that occurs during a decomposition reaction using the
provided equation as an example.
In a decomposition reaction, a compound breaks down into simpler
substances, as seen when Fe(OH)3 breaks down into Fe2O3 and
H2O.
In a decomposition reaction, elements combine to form a compound.
In a decomposition reaction, two compounds react to form a single
product.
In a decomposition reaction, ions exchange partners to form new
compounds.
6. A substance has a melting point of -7°C and a boiling point of 59°C. What is
its state at room temperature (20°C)?
Solid
Gas
Liquid
7. Mass, volume, and the amount of energy in a substance are ___________
properties
chemical
extensive
physical
intensive
,8. In a laboratory experiment, if the temperature of the system containing H2(g)
and F2(g) is raised significantly, what would you expect to observe in terms of
reactant and product concentrations?
The concentrations of both reactants and products will remain
unchanged.
The concentration of products will increase while the concentration of
reactants will decrease.
The reaction will stop completely and no changes will occur.
The concentration of reactants will increase while the concentration
of products will decrease.
9. If SnCl2 is dissolved in water, what type of ions would you expect to form in
solution, and how would this affect the solution's conductivity?
You would expect to form only neutral molecules, which would not
affect conductivity.
You would expect to form Sn^2+ and Cl^- ions, which would increase
the solution's conductivity.
You would expect to form Cl2 gas, which would increase the solution's
conductivity.
You would expect to form Sn^2+ ions only, which would decrease
conductivity.
10. Describe how the average atomic mass of an element is calculated using its
isotopes and their relative abundances.
The average atomic mass is determined by the number of protons in
the nucleus.
The average atomic mass is the sum of all isotopes' masses without
considering their abundances.
, The average atomic mass is simply the mass of the most abundant
isotope.
The average atomic mass is calculated by multiplying the atomic
mass of each isotope by its relative abundance and then summing
these values.
11. What is the formula used to convert molecules to moles?
Number of moles = Number of molecules / Avogadro's number
Number of moles = Number of molecules - Avogadro's number
Number of moles = Number of molecules + Avogadro's number
Number of moles = Number of molecules x Avogadro's number
12. What is the formula of the ioinic compound formed when ions of calcium
and nitrogen combine?
Ca3N2
Ca2N
CaN2
Ca2N3
CaN
13. What is the pH of a solution if it has [OH-] =2.52x10-2 M? Is it acidic or basic?
1.60; acidic
12.4; basic
12.4; acidic
1.60; basic
