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WorksheetsUnit #3; Chemical Reactions
Total questions: 50
Worksheet time: 25mins
Which of the following means heat is given-off from a reaction?
ectothermic
exothermic
introthermic
endothermic
How many of the following are ways to speed up a chemical reaction?
agitation
heat
adding another reactant
adding a catalyst
3 of these
If H2SO4 and Al together, which of the 3 commonly formed gases COULD NOT be a potential product?
Hydrogen
Carbon Dioxide
Nitrogen
Oxygen
If you add H2O2 and H2CO3 together, which of the 3 commonly formed gases COULD NOT be a potential product?
Oxygen
Carbon
Hydrogen
Carbon Dioxide
All 3 are possible products
What is a positive wooden splint test for the formation of Oxygen gas?
flame gets bigger
flame is extinguished
mini explosion
none of these
Which of the following gases would be a product if when tested with a LIT splint, the flame goes out?
Carbon
Oxygen
Hydrogen
Carbon Dioxide
Water
If Na and H2O are combined and the test with the LIT splint results in a loud noise, which gas is a product?
Carbon
Nitrogen
Carbon Dioxide
Oxygen
none of these
Which of the following would indicate that a chemical reaction has NOT taken place?
ice cube melts
wood is burned
combining 3 liquids in a closed container makes the container begin to EXPAND
combining 2 liquids that are transparent produces a non-transparent product
all of the above
When you combine Gold and Mercury what is formed?
a compound
a mixture
a molecule
none of these
Which evidence of chemical reaction can be observed when Mercury and Aluminum are combined?
forms a gas
forms a precipitate
change in temperature
unexpected color change
Combining CuSO4 and Aluminum produces a/n _________ _________.
reddish-brown precipitate
hazardous gas
glowing light
decrease in temperature
Why does a light stick eventually "BURN OUT?"
the glass inside breaks down
the products formed have more energy than the reactants
one or more of the reactants is consumed
the temperature decreases
How many elements and total atoms are there in the formula: (NH4)3PO4
3, 20
4, 20
3, 19
4, 19
How many elements and total atoms are there in the formula: HC2H3O2 ?
4, 7
3, 7
4,8
3, 8
Which of the following is true?
The arrow in a chemical equation always points from left to right.
If there are 3 reactants, there must be 3 products in a chemical equation.
The number of elements in the reactants must equal the number of elements in the products in a chemical equation.
none of these
When reading a chemical formula, which of the following is true?
The subscripts tell you the number of atoms of each element in the compound.
If there is no subscript for an element, it means that there are 0 atoms of that element in the compound.
There are always the same number of each element in a compound.
The number of total elements in a compound must equal the number of total atoms.
A chemical equation represents what?
physical change
atoms breaking and re-forming
a breaking and re-forming of bonds
none of these
Which evidence of chemical reaction did you observe in the Luminol video?
formation of a gas
formation of a precipitate
formation of light
none of these
When you activate a "glow stick," what is actually happening?
You ignite a flame inside the tube.
You make the wires connect to the battery inside.
You allow the chemicals inside the glass tube and the surrounding area to combine.
You flip a switch to turn-on a light inside.
Which of the following did you observe when CuSO4 and NH3 were combined?
formation of light
formation of a precipitate
unexpected color change
A and B
2 of these
If you combine H2SO4 and Cu, what gases are possible products?
H2 and O2
H2
H2, O2 C
O2
H2, O2 and CO2
When H3PO4 and Fe are combined, and a lit split makes a popping noise, what is the gas product AND what elements would be leftover in the products?
H2
O2
H2O
CO2
Which of the following is true of a chemical equation that has 3 reactants, 12 atoms and 4 elements?
There must be 3 products.
There must be 3 products and 4 elements in the products.
There must be 3 products and 12 atoms in the products.
The products must contain 4 elements.
When bonds are broken and reformed, a chemical ___________ has taken place and it is represented by a chemical _________________.
reaction, equation
reaction, formula
change, formula
change, reactant
In adding Ammonia to Copper Sulfate, ______ evidences of chemical change are witnessed including what?
3, formation of a gas
2, formation of a gas
2, unexpected color change
3, unexpected color change
Goggles must be worn any time you are using what 3 things?
chemicals or flames
chemicals or glass
chemicals or heat
chemicals, heat or glass
chemicals, flames or glass
For how long must you use the eyewash if you splash a chemical in your eye/s?
10 minutes
20 minutes
30 minutes
20 minutes or longer if your eye/s still hurt!!!
The HCS Pictogram that warns of DNA damage is a picture of what?
head and shoulders
skull and crossbones
DNA and cells
exclamation point
Which HCS Pictogram represents a risk of gases in closed containers exploding?
corrosion
exploding bomb
gas cylinder
oxidizing flame
Which of the following HCS Pictograms represents the highest risk to your IMMEDIATE health?
head and shoulders
exploding bomb
skull and crossbones
flame with circle
When you stop, drop and roll, you decrease the amount of which reactant in a combustion reaction?
carbon
carbon dioxide
water
oxygen
A/n_____________ reaction represents energy being released and a/n __________________ reaction represents energy being absorbed.
chemical, temperature
endothermic, exothermic
chemical, exothermic
exothermic, endothermic
chemical, endothermic
Which of the following is true?
In a chemical equation, bonds are broken and reformed in the products.
In a chemical equation, bonds are broken in the reactants.
In a chemical equation, bonds are broken in the reactants and re-formed in the products.
none of these
Which of the following is true?
The arrow of a chemical equation would point from right to left if the products were written first.
The arrow of a chemical equation always points towards the reactants.
The arrow of a chemical reaction always points to the right.
None of these
A chemical ______________ is a representation of atoms.
reaction
equation
formula
molecule
In some of the labs that we did, I had dissolved a solid in water to make a _____________. In the chemical equation how is that represented?
triangle
+ sign
arrow
dot
What does "Halogen" mean and what family of elements on the periodic table combines the easiest with a Halogen?
gas, 1
gas, 2
salt-forming, 1
salt-forming, 2
How do you recognize the formula of an acid?
first element is Hydrogen
first element is a metal
first element is a non-metal
none of these
Which of the following is true if a liquid becomes blue with Universal Indicator?
Liquid is an acid and the pH is below 7
Liquid is a base and the pH is below 7
Liquid is an acid and the pH is above 7
Liquid is a base and the pH is above 7
In the "Rainbow Reaction" in a baggie, which of the following was true?
it was an exothermic reaction
a precipitate was formed
both solids dissolved in the Universal Indicator
3 evidences of chemical reaction were witnessed
Which of the following is an evidence of chemical change/reaction?
mixing 2 solids
bubbles forming
change of color from yellow to blue
container expanding
In the "ChemSpider" structures, which element made the most bonds which is why it was in the middle/center of the structures?
Carbon
Hydrogen
Nitrogen
Oxygen
In the "ChemSpider" structures, which element was always found around the outside of the structures because it can only make one bond.
Carbon
Hydrogen
Nitrogen
Oxygen
How many elements and total atoms are in the following equation?
HBrO4 + Ga2(CO3)3 yields H2O + GaBr3 + CO2
6, 30
5, 30
6, 28
6, 29
If H3P and a metal are combined and a gas is formed, which of the following is true?
the gas formed is Hydrogen
the gas is oxygen
the gas will extinguish a flame
the gas formed is H2O
How many diatomic molecules are there and they include which of the following?
4, Hydrogen and Oxygen
4, all of the Halogens
7, Bromine and Oxygen
7, Nitrogen and Carbon Dioxide
Which of the following is true regarding diatomic molecules?
They are always written first in a chemical equation.
They always have a subscript of 2 whether they are bonded to another atom or not
They are all metals.
When not bonded to other elements, they have a subscript of 2.
Which of the following is true?
An arrow represents change and a triangle represents temperature.
An arrow represents breaking of bonds and a triangle represents change.
A triangle represents a chemical reaction.
A triangle represents a chemical equation.
How many OSHA Pictograms are there and which one have "WE" seen the most when using the chemicals in lab?
8
health hazard
9
acture toxicity
9
exclamation point
8
health hazard
What does MSDS stand for? and how many sections does one contain?
Molecule Safety Data Substances
16
Material Substances Data Safety
15
Material Safety Data Sheet
16
Material Substances Data Storage
15
