High School Chemistry Practice Questions

High School Chemistry questions are on the Alberta PAT, NLN PAX, HESI, DET, HOAE, HOBET and TEAS

as well as most High School tests

1. What are the differences, if any, between mixtures and compounds?

a. A mixture is homogeneous, and the properties of its components are retained, while a compound is heterogeneous and its properties are distinct from those of the elements combined in its formation.
b. A mixture is heterogeneous, and the properties of its components are retained, while a compound is homogeneous and its properties are distinct from those of the elements combined in its formation.
c. A mixture is heterogeneous, and the properties of its components are changed, while a compound is homogeneous and its properties are similar to those of the elements combined in its formation.
d. A compound is heterogeneous, and the properties of its components are retained, while a mixture is homogeneous and its properties are distinct from those of the elements combined in its formation.

2. What are the differences, if any, between chemical changes and physical changes?

a. During a physical change, some aspect of the physical properties of matter are altered, but the identity of the substance remains constant. Chemical changes involve the alteration of both a substance’s composition and structure.
b. During a chemical change, some aspect of the physical properties of matter are altered, but the identity of the substance remains constant. Physical changes involve the alteration of both a substance’s composition and structure.
c. During a physical change, no aspects of the physical properties of matter are altered, but the identity of the substance remains constant. Chemical changes involve the alteration of both a substance’s composition and structure.
d. There is no substantive difference between chemical and physical changes.

3. H = H_products – H_reactants is the formula used to determine a ______________.

a. Change in hydration
b. Change in haploid bond
c. Change in heat content
d. Change in hypothesis

4. In an _______ reaction, the heat content of the products is ______ than the heat content of the reactants, while in an _________ reaction, the heat content of the products is ______ than the heat content of the reactants.

a. Exothermic, greater, endothermic, less
b. Endothermic, less, exothermic, greater
c. Exothermic, greater, exothermic, less
d. Endothermic, greater, exothermic, less

5. The equation E = mc² is based on the ______________________, and states that ______equals _____ times the _____________².

a. The equation E = mc2 is based on the 2nd Law of Thermodynamics, and states that Mass equals Energy times (the Velocity of light) ².
b. The equation E = mc2 is based on the Law of Conservation of Mass and Energy, and states that Energy equals Mass times (the Velocity of light) ².
c. The equation E = mc2 is based on the 1st Law of Thermodynamics, and states that Mass equals Energy times (the Velocity of sound) ².
d. The equation E = mc2 is based on the Law of Conservation of Mass and Energy, and states that the Velocity of light equals Energy times (the Mass) ².

6. When a measurement is recorded, it includes the _________ ________, which are all the digits that are certain plus one uncertain digit.

a. Major figures
b. Significant figures
c. Relative figures
d. Relevant figures

7. The _______ _______ is based on the lowest theoretical temperature, called ________ _______.

a. Kelvin scale, absolute zero
b. Celsius scale, absolute zero
c. Kelvin scale, boiling point of water
d. Centigrade scale, freezing point of water

8. Through experiments and calculations, ________ ______ has been verified to be _________o on the _________ scale.

a. Through experiments and calculations, absolute zero has been verified to be – 273.15o on the Celsius scale.
b. Through experiments and calculations, unconditional zero has been verified to be 0o on the Kelvin scale.
c. Through experiments and calculations, absolute null has been verified to be -100o on the Celsius scale.
d. Through experiments and calculations, absolute zero has been verified to be – 273.15o on the Kelvin scale.

9. When using the scientific notation system to express large numbers, move the _______ ______ until _____ digit(s) remain(s) to the left, then indicate the number of moves of the decimal point as the _______ __ ___.

a. When using the scientific notation system to express large numbers, move the decimal point until only two digits remain to the left, then indicate the number of moves of the decimal point as the exponent of 10.
b. When using the scientific notation system to express large numbers, move the decimal until only one digit remains to the left, then indicate the number of moves of the decimal point as the exponent of 2.
c. When using the scientific notation system to express large numbers, move the decimal until only three digits remain to the left, then indicate the number of moves of the decimal point as the exponent of 10.
d. When using the scientific notation system to express large numbers, move the decimal until only one digit remains to the left, then indicate the number of moves of the decimal point as the exponent of 10.

10. In science, ________ indicates the __________ or ___________ of a measurement, while _______ indicates the ________ of a measurement to its known or accepted value.

a. In science, accuracy indicates the reliability or reproducibility of a measurement, while precision indicates the proximity of a measurement to its known or accepted value.
b. In science, exactitude indicates the reliability or reproducibility of a measurement, while contiguity indicates the remoteness of a measurement to its known or accepted value.
c. In science, precision indicates the reliability or reproducibility of a measurement, while accuracy indicates the proximity of a measurement to its known or accepted value.
d. In science, uncertainty indicates the realism or possibility of a measurement, while precision indicates the distance of a measurement to its known or accepted value.

11. The _________________ states that, in a chemical change, ________ can be neither _____ or ________, but only changed from _______________.

a. The Law of the Preservation of Matter states that, in a chemical change, energy can be neither created nor destroyed, but only changed from one form to another.
b. The Law of the Conservation of Energy states that, in a chemical change, energy can be neither created nor destroyed, but only changed from one atomic number to another.
c. The Law of the Conservation of Energy states that, in a chemical change, energy can be neither created nor destroyed, but only changed from one form to another.
d. The Law of the Conservation of Energy states that, in a chemical change, energy can be neither duplicated nor destroyed, but only changed from one form to another.

12. A _________ is a process that transforms one set of chemical substances to another; the substances used are known as ________ and those formed are _________.

a. A chemical change is a process that transforms one set of chemical substances to another; the substances used are known as products and those formed are reactants.
b. A biological change is a process that transforms one set of chemical substances to another; the substances used are known as reactants and those formed are products.
c. A chemical change is a process that transforms one set of chemical substances to another; the substances used are known as reactants and those formed are products.
d. A chemical variation is a process that transforms one set of chemical substances to another; the substances used are known as reactants and those formed are products.
13. ________ is the series of chemical reactions resulting in the ______ of organic compounds, and _________ is the series of chemical reactions that _________ larger molecules.

a. Anabolism is the series of chemical reactions resulting in the synthesis of inorganic compounds, and catabolism is a series of chemical reactions that break down larger molecules.
b. Anabolism is the series of chemical reactions resulting in the synthesis of organic compounds, and catabolism is a series of chemical reactions that combine larger molecules.
c. Catabolism is the series of chemical reactions resulting in the synthesis of organic compounds, and anabolism is a series of chemical reactions that break down larger molecules.
d. Anabolism is the series of chemical reactions resulting in the synthesis of organic compounds, and catabolism is a series of chemical reactions that break down larger molecules.

14. A(n) _______ is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are ________ and reactions ____________.

a. A propellant is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are weakened and reactions accelerated.
b. A reagent is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are strengthened and reactions accelerated.
c. A catalyst is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are weakened and reactions slowed.
d. A catalyst is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are weakened and reactions accelerated.

15. _________ is the most abundant element in the Earth’s crust and appears on the Atomic Table as the letter ____.

a. Nitrogen, N
b. Oxygen, O
c. Silicon, Si
d. Sodium, Na

16. ___________________ states that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

a. The Law of Multiple Proportions
b. The Law of Definite Proportions
c. The Law of the Conservation of Energy
d. The Law of Averages

17. ___________________ states that every chemical compound contains fixed and constant proportions (by weight) of its constituent elements.

a. The Law of Multiple Proportions
b. The Law of the Preservation of Matter
c. The Law of the Conservation of Energy
d. The Law of Definite Proportions

18. ___________________ states that, in a given _____, __________ can have the ___________.

a. The Law of Definite Proportions states that, in a given atom, no two electrons can have the same set of four quantum numbers.
b. The Pauli Exclusion Principle states that, in a given atom, no four electrons can have the same set of two quantum numbers.
c. The Pauli Exclusion Principle states that, in a given molecule, no two electrons can have a different set of four quantum numbers.
d. The Pauli Exclusion Principle states that, in a given atom, no two electrons can have the same set of four quantum numbers.

19. According to the tenets of Dalton’s atomic theory, which of the following is true:

a. All matter is made up of tiny, interconnected particles called atoms.
b. All atoms of an element are alike in weight, and this weight is specific to the kind of atom.
c. Atoms can be subdivided, created, or destroyed.
d. In chemical reactions, atoms are not combined, separated, or rearranged.

20. Atoms of _________ __________ combine in ________ ________ ratios for from chemical ________.

a. Atoms of different elements combine in simple whole-number ratios to form chemical compounds.
b. Atoms of different components combine in simple fractional ratios to form chemical compounds.
c. Atoms of the same element combine in simple whole-number ratios to form chemical compounds.
d. Atoms of different elements combine in simple whole-number ratios to form chemical mixtures.

1. B
A mixture is heterogeneous, and the properties of its components are retained, while a compound is homogeneous and its properties are distinct from those of the elements combined in its formation.

2. A
During a physical change, some aspect of the physical properties of matter are altered,       but the identity of the substance remains constant. Chemical changes involve the   alteration of both a substance’s composition and structure.

Note:  Examples of physical changes include breaking glass, cutting wood and melting ice. Sometimes, the process can be easily reversed. Restoration of the original form is not possible following a chemical change.

3. C 

H = H_products  –  H_reactants is the formula used to determine a change in heat content.

4.  D 
In an Endothermic reaction, the heat content of the products is greater than the heat content of the reactants, while in an exothermic  reaction, the heat content of the products is less than the heat content of the reactants.

Because it is virtually impossible to measure the total energy of molecules, the experimental data typically used with reactions is the change in heat content known as enthalpy.

5. B
The equation E = mc2 is based on the Law of Conservation of Mass and Energy, and states that Energy equals Mass times the Velocity of light.

6.  B
When a measurement is recorded, it includes the significant figures, which are all the digits that are certain plus one uncertain digit.

7.  A
The Kelvin scale is based on the lowest theoretical temperature, called absolute zero.

8.  A
Through experiments and calculations, absolute zero has been verified to be – 273.15^o on the Celsius scale.

9.  A
When using the scientific notation system to express large numbers, move the decimal point until only two digits remain to the left, then indicate the number of moves of the decimal point as the exponent of 10.

10.  C
In science, precision indicates the reliability or reproducibility of a measurement, while accuracy indicates the proximity of a measurement to its known or accepted value.

Note:  Regardless of the precision or accuracy of a measurement, all measurements include a degree of uncertainty, dependent on limitations of the measuring instrument and the skill with which the measurement is completed.

11.  C
The Law of the Conservation of Energy states that, in a chemical change, energy can be neither created nor destroyed, but only changed from one form to another.

12.  C
A chemical change is a process that transforms one set of chemical substances to      another; the substances used are known as reactants and those formed are products.

13.  D
Anabolism is the series of chemical reactions resulting in the synthesis of organic compounds, and catabolism is a series of chemical reactions that break down larger molecules.

14.  D
A catalyst is a chemical involved in, but not changed by, a chemical reaction by which chemical bonds are weakened and reactions accelerated.

Note:  Enzymes function as organic catalysts and allow many chemical reactions to occur within the homeostatic constraints of a living system. Enzymes can act rapidly, as in the case of carbonic anhydrase (enzymes typically end in the -ase suffix), which causes the chemicals to react 107 times faster than without the enzyme present.

15.  B
Oxygen is the most abundant element in the Earth’s crust and appears on the Atomic Table as the letter O.

16.  A
The Law of Multiple Proportions states that when two elements combine with each other to form more than one compound, the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.

17.  D
The Law of Definite Proportions states that every chemical compound contains fixed and constant proportions (by weight) of its constituent elements.

Note:  Although many experimenters had long assumed the truth of the principle in general, the French chemist Joseph-Louis Proust first accumulated conclusive evidence for it in a series of researches on the composition of many substances, especially the oxides of iron (1797).

18. C
The Pauli Exclusion Principle states that, in a given molecule, no two electrons can have a different set of four quantum numbers.

19. B
According to the tenets of Dalton’s atomic theory, All atoms of an element are alike in weight, and this weight is specific to the kind of atom.

20.  A
Atoms of different elements combine in simple whole-number ratios to form chemical compounds.