Chemical Reactions Quiz

Question 1

what does aq in brackets mean

Answer 1

it dissolves in water and its in a solution

Question 2

what is the law of conservation of mass

Answer 2

states that matter cannot be created nor destroyed, and can only change forms

Question 3

what makes up a reaction system

Answer 3

reactants and products

Question 4

what does the total mass of reactants equal

Answer 4

total mass of products

Question 5

what is the purpose of coefficients in skeleton equations

Answer 5

makes sure law of conservation of mass is obeyed

Question 6

what do the coefficients tell you in a skeleton equation

Answer 6

the total amount of those molecules in the reaction

Question 7

what is the difference between the coefficient and subscript in a skeleton equation

Answer 7

subscript tells you how many of each atom are in the compound, coefficient tells you how many of the molecule/compounds are in the reaction

Question 8

what do you have to make sure of when balancing a chemical equation

Answer 8

that you have the same amount of each individual element on both sides of the equation

Question 9

how do you find how many of each individual element you have in the reaction

Answer 9

multiply the coefficient by the subscript

Question 10

what splits the different elements or compounds that are not combined into one in the reactant state

Answer 10

a plus sign

Question 11

what are the general rules of balancing

Answer 11

• balance atoms/ions you have the most of first
• coefficient always goes at the beginning of the compound
• no fractions
• always have coefficients in the lowest whole number ratios
• balance combustion reactions in alphabetical order based on the chemicals, with oxygen always being last

Question 12

how can you use nomenclature when writing balanced chemical reactions

Answer 12

to identify ionic, molecular and acidic compounds

Question 13

how can the solubility table help you when writing balanced chemical reactions

Answer 13

to predict aqueous or solid for ionic compounds reacting in water

Question 14

how do reaction types help you write balanced chemical reactions

Answer 14

allows you to predict products

Question 15

what is the purpose of balancing chemical equations

Answer 15

to obey the law of conservation of mass

Question 16

how do you determine the state of a product if it is ionic

Answer 16

• assume it is solid as a pure substance
• if part of a reaction in water, use solubility table
• reactants are aqueous

Question 17

how do you determine the state of a product if it is molecular

Answer 17

• use any info from question and databook

- never assume state (if it doesn’t tell you what it is, then just done include state)

Question 18

what are molecular elements

Answer 18

elements that always exist as molecular atoms and are never found on their own

Question 19

what are some examples of chemical reactions around us

Answer 19

fireworks, glowsticks, airbags, adhesives, hadnwarmers

Question 20

what are two examples of chemical reactions in the natural world

Answer 20

photosynthesis and cellular respiration

Question 21

what are the two ways to show a chemical reaciton

Answer 21

word equation or skeleton equation

Question 22

how do you read reaction equations

Answer 22

everything on the left of the arrow is the reactants, everything on the right of the arrow is the products

Question 23

whats a chemical reaction

Answer 23

involves rearranging of atoms to create new substances and is usually irreversible

Question 24

what is some evidence of chemical change

Answer 24

temperature increase, emission of light or sound, production of electrical energy, decrease in temperature, production of nan odour, colour change, formation of gas, bubbles, formation of precipitate

Question 25

what are the different types of chemical reactions

Answer 25

formation, decomposition, single replacement, double replacement, combustion

Question 26

whats a formation reaction

Answer 26

when two or more elements or two or more simple compounds react to produce one compound or one more complex compound

Question 27

whats a decomposition reaction

Answer 27

when one compound decomposes to produce its constituent elements or to form a simpler substance

Question 28

whats a single replacement reaction

Answer 28

when an element reacts with compound to produce a different compound and a different element

Question 29

what replaces what in a single replacement reaction

Answer 29

the metal will always replace the metal in the compound or the non-metal will always replace the non-metal in the compound

Question 30

whats a double replacement reaction

Answer 30

when two compounds react to produce two different compounds

Question 31

why will cations or anions never combine

Answer 31

because they are the same charge and will repel each other

Question 32

where are anions written in a chemical formula

Answer 32

second

Question 33

whats a combustion reaction

Answer 33

a compound or element reacting with oxygen to produce oxides of the elements in the reactant

Question 34

what are the by-products of complete combustion

Answer 34

water and carbon dioxide

Question 35

whats hydrocarbon combustion

Answer 35

any sort of hydrocarbon reacting with oxygen

Question 36

whats hydrocarbon

Answer 36

any combination of hydrogen and carbon

Question 37

when does complete combustion occur

Answer 37

when carbon and hydrogen react with oxygen

Question 38

how do you predict a decomposition reaction

Answer 38

if you see one reactant

Question 39

how do you predict double replacement

Answer 39

when there are two ionic compounds reacting with each other

Question 40

how do you predict complete combustion

Answer 40

when you see a hydrocarbon reacting with oxygen

Question 41

how do you predict combustion

Answer 41

when you see anything reacting with oxygen

Question 42

how do you predict single replacement

Answer 42

when you see one element on its own reacting with a compound

Question 43

how do you predict formation

Answer 43

if you see just two elements reacting with each other