Exam 3 Chemical Reactions

Question 1

What Three different kinds of equations are used to represent chemical reactions in aqueous solution: __________________

Answer 1

Molecular equation
Ionic
and Net Ionic

Question 2

A ___________________ is a chemical equation showing the complete, neutral formulas for every species in a reaction.

Answer 2

molecular equation

Question 3

Classify the following reaction
A) decomposition
B) gas forming
C) combination
D) percipitation

Answer 3

B) gas forming

Question 4

A reaction in which two aqueous salt solutions combine to form an insoluble salt is called, ___________________

Answer 4

precipitation reaction

Question 5

Is this a single replacement reaction? why?

Answer 5

yes,

Question 6

________________ Ions that are the same on both sides of an ionic equation

Answer 6

spectator ions

Question 7

___________ An equation that shows the formulas of all the species involved in a chemical reaction

Answer 7

molecular equation

Question 8

An equation that shows all the ions as well as other species involved in a chemical reaction

Answer 8

ionic equation

Question 9

An equation that shows only the species that are involved in the change that occurs during a chemical reaction

Answer 9

net ionic equation

Question 10

In a single- replacement reaction, sodium metal reacts with water to form aqueous sodium hydroxide as one of the products. Which equation below correctly represents this reaction?

Answer 10

C)

Question 11

which of the following two solutions will result in the formation of a precipitate when they are mixed?

Answer 11

A)

Question 12

The following repersents a ______ ______ equation.

Answer 12

net ionic equation

Question 13

K is an example of a _______ ion.

Answer 13

spectator ion

Question 14

What will be the net ionic equation for this reaction?

Answer 14

B)

Question 15

What is the identity of the gas that is produced when a lithium sulfite solution and hydrochloric acid are mixed?

A) sulfur dioxiode
B) sulfur trioxide
C) chlorine

Answer 15

A) sulfur dioxide

Question 16

What is evidence of a chemical reaction?
A) a color change during a reaction
B) formation of precipitate
C) the sublimation of a solid to a gas
D) Both A and B

Answer 16

D) Both A and D

Question 17

The ______ quantity must always be the same on both sides of a balanced chemical equation?

Answer 17

The number of each type of atom

Question 18

What are the coefficients, written from left to right that will correctly balance the following equation?

Answer 18

2, 9, 6, 8

Question 19

Answer 19

2

Question 20

This reaction is a good example of a ________ reaction:
A) combustion
B) decomposition

Answer 20

B) decomposition reaction

Question 21

When C3H8 burns completely in oxygen, what are the likely products?
_____________ and _____________

Answer 21

CO2 and H2O

Question 22

True/False
An example of a correctly balanced reaction of solid copper reacting with solid sulfur to form solid copper(I) sulfide.

Answer 22

True

Question 23

True/False
An example of a correctly balanced reaction of solid copper reacting with solid sulfur to form solid copper(I) sulfide.

Answer 23

True

Question 24

True/False
An example of a correctly balanced reaction of solid copper reacting with solid sulfur to form solid copper(I) sulfide.

Answer 24

False

Question 25

True/False
An example of a correctly balanced reaction of solid copper reacting with solid sulfur to form solid copper(I) sulfide.

Answer 25

False

Question 26

If solid lithium hydrogen carbonate decomposes upon heating to form solid lithium oxide, gaseous carbon dioxide, and liquid water, which reaction below is the complete and balanced molecular equation for the process?

Answer 26

Option 4 with the LIzO(solid) at the end and the 2 Li at the beginning

Question 27

Answer 27

C)

Question 28

Answer 28

C)

Question 29

Only C is an example of a _____________ and _______________ reaction

Answer 29

combination and combustion reaction

Question 30

An ______________________ (or complete ____________) is a chemical equation showing all of the species as they are actually present in the solution. When a soluble ionic compound is placed in water, the cations and anions dissociate (that is, separate from each other) resulting in just ions in solution.

Answer 30

ionic equation

Question 31

So, when writing _____________, only strong acids and soluble ionic compounds (that is, strong electrolytes) are separated into ions because that is how they exist in the solution. All other species will remain as they appear in the molecular equation. The following is the __________ for the molecular equation for the reaction between silver nitrate and magnesium chloride shown above.

Answer 31

ionic equation

Question 32

A _____ ____________ ___________ is an equation showing only the species that actually participate in the reaction. Ions that are the same on both sides of the equation are called spectator ions because they are not participating in the reaction.

Answer 32

net ionic equation

Question 33

The ____________ ____________ __________can be obtained from the complete ionic equation which is written from the molecular equation.

Answer 33

net ionic equation

Question 34

True/False Spectator ions are removed from the ionic equation in order to get the net ionic equation AND if the coefficients can be reduced to simple whole numbers that they should be reduced.

Answer 34

both are True

Question 35

In a physical change matter changes its appearance but not its _________________. For example, ice melts but water is still ice and ice is still water. The chemical properties of H2O are the same regardless of it being ice, water, or steam.

Answer 35

composition

Question 36

In a chemical change matter changes ________________. Matter changes by undergoing a _____________ reaction. Where reactants present result in other substances called ___________. for example copper turns green upon continued exposure to air because it reacts with gases in air to form new compounds.

Answer 36

composition
products

Question 37

A physical change results in a different __________ of the same substance, while a chemical change results in their fundamental associations changing resulting in a new identity.

Answer 37

form
identity

Question 38

Explain what’s happening in the photo

Answer 38

the combustion of butane produces heat by the following reaction
2 C4H10 +13O2 —–8 CO2+10 H2O.

If you use a lighter, you push the button and turn the flint trigger that sparks at the same time which produces a flame. The flame is produced bc of the spark and since butane molecules are FLAMMABLE molecules. The butane molecules are also reacting with the oxygen in the air to form new molecules. The new molecules released from the combustion of butane molecules is carbon dioxide and water. (CO2 H2O)

Question 39

the following symbols designate the state of matter
(g) gas
(l) liquid
(s) solid
(aq) means what?

Answer 39

aq designates an aqueous solution.
This abbreviation indicates that a substance is dissolved in water. When a substance dissolves in water, the mixture is called a solution.

Question 40

To balance an equation (in order to show the reality of chemical reactions where matter must be conserved) we insert ___________ not subscripts in front of the chemical formulas as needed inorder to make the number of each type of atom in the reactants equal to the number of each type of atom in the products.
Multiply the ____________ by the subscript of an atom in order to determine the number of atoms.

Answer 40

coefficients

WHY: Change only the coefficients because changing the subscripts changes the KINDS of molecules not the number.

Question 41

The following equation shows the chemical reaction of methane gas, reacting with oxygen, to form carbon dioxide and water, such as on a kitchen stove.
WRITE A BALANCED EQUATION

Answer 41

Question 42

In order for this equation to be balanced, the coefficient x must be
a) 3
b) 6
c) 9
d) 12

Answer 42

6
because the Ox on the reactant side has 18 atoms. on the product side its 8. the O2’s coefficient would be 6. bc 6*2=12 plus 6 from the CHO molecule. thus getting 18 atoms

Question 43

Write a balanced equation for the reaction of solid aluminum with aqueous sulfuric acid to form aqueous aluminum sulfate and hydrogen gas.

Answer 43

steps 1) write the correct chemical compounds

2) balance the free elements last. Sulfur and oxygen occur in only one compound on each side of the equation so balance them first.
3) balance polyatomic ions as one unit. therefore put 3 infront of SO and 3 infront of HSO
4) balance Al next. 2 Al atoms on the right side of the equation, place a 2 infront of Al on the left.
5) balance H next. 6 H on the left side. put 3 on the left

Question 44

Write a balanced equation for the reaction of aqueous lead (II) acetate with aqueous potassium iodide to form solid lead (II) iodide and aqueous potassium acetate

Answer 44

here’s each step in the equation

Question 45

Chemistry is the science that studies the connections between the properties of _________ and the particles that compose that __________.

Answer 45

matter
matter