Chemical Reactions and Balancing

Question 1

What are the 4 ways to know a chemical reaction has occurred?

Answer 1

gas released
permanent color change
solid formed
heat/light

Question 2

Which side of the equation is the reactant and which side is the product?

Answer 2

Reactant = left side
Product = right side

Question 3

What do the coefficients in a chemical equation tell us?

Answer 3

how many of the element/compound there is

Question 4

What are the physical states?

Answer 4

Solid
Liquid
Gas
Aqueous

Question 5

How ever many atoms you see at the beginning is the _____ amount that must come out at the end

Answer 5

same

Question 6

What do the subscripts tell you?

Answer 6

Tell you how many of each atom or group

Question 7

Coefficients tell you how many of ____

Answer 7

That specific compound

Question 8

Na + Cl2 ——–> __________

Answer 8

2NaCl

Question 9

Mg + F2——–> ____________

Answer 9

MgF2

Question 10

When balancing equations what must you never bring over?

Answer 10

Never bring over the subscript

Question 11

What is the only exception for not bringing over the subscript?

Answer 11

Polyatomic elements, those you need to bring over the subscript because it is part of the whole thing

Question 12

Al + O2 ———> ____________

Answer 12

2Al2O3

2 Al (subscript 2) O3

Question 13

When balancing an equation what must you do before you even begin to balance?

Answer 13

You must make sure the charges are balanced on the left

Question 14

C2H5OH + O2 ——–> ___________

Answer 14

2CO (subscript 2) + 3H2O

Question 15

K + HOH ——–> _________

Answer 15

2KOH+H2

Question 16

When balancing equations you must never go over ______

Answer 16

6

Question 17

NH3 + O2 ——–> NO + H2O

Answer 17

4NH3 + 5O2 ——-> 4NO + 6H2O

Question 18

What is a combination reaction?

Answer 18

A + Z —–> AZ

Elements combine to make compounds

Question 19

What kinds of substances usually form combination reactions?

Answer 19

Simple substances

Question 20

H2 + O2 ——-> __________

Answer 20

2H2O

Question 21

H2 + N2 ——-> _____________

Answer 21

2NH3

Question 22

What is a decomposition reaction?

Answer 22

One thing breaking down into many

A single compound being broken down into two or more simpler substances

Question 23

Most _____ reactions are unpredictable

Answer 23

Decomposition

Question 24

What is the exception to the unpredictability of decomposition reaction?

Answer 24

metal hydrogen carbonate——-> metal carbonate + H2O (g) + CO2(g)

AND

metal carbonate (s) ——-> metal oxide (s) + CO2 (g)

Question 25

What is a single replacement reaction?

Answer 25

A + Bx --------> B + Ax one element replaces another

Question 26

In single replacements the _____ goes with the ______

Answer 26

metal, nonmetal

Question 27

How do you recognize a single replacement?

Answer 27

A single element + a compund

Question 28

What is a double replacement?

Answer 28

Ax (Aqueous) + By (aqueous) --------> Ay + Bx Two aqueous mix and a PPT forms Two compunds

Question 29

In Double replacement we have to ______

Answer 29

FOIL First, Outer, Inner, Last

Question 30

What is a neutralization reaction?

Answer 30

Acid + Base -------> Salty Water

Question 31

Groups 1 and 2 are _____ (More/Less) reactive than Transition metals are _____ (more/less) reactive than Noble metals

Answer 31

more, more,

Question 32

In Double Replacement how do we know which is the PPT?

Answer 32

You follow the solubility rules

Question 33

Solubility Rules:

Answer 33

1. All Na+, K+, NH4+, H+ all soluble 2. All NO3-, C2H3O2-, ClO4- soluble 3. All Ag+, Hg(2+ charge), Pb (2+ charge), Pb (4+ charge) insoluble 4. All Cl-, Br-, I- soluble 5. All CO3 (2- charge), O(2- charge), S (2- charge), OH-, PO4(3-charge) insoluble 6. All SO4 (2- charge) except (Ca(2+ charge), Ba (2+charge)) soluble 7. if not here assume insoluble

Question 34

All Nitrates are _____

Answer 34

Soluble