WorksheetsUnit 4: Chemical Reactions Review
Total questions: 24
Worksheet time: 28mins
Which observation does NOT indicate a chemical reaction has taken place?
formation of a precipitate
production of a gas
production of heat and/or light
change in the total volume of the substances
A solid produced as a result of the reaction between two aqueous solutions is
a precipitate.
a reactant.
a molecule.
a soluble product.
What does the symbol “g” beside a formula in a chemical equation represent?
the substance is a gas
the chemical produces heat
the chemical is dissolved
the chemical is a catalyst in water
A catalyst is _________________.
the product of a combustion reaction
used to speed up a reaction
a reactant in a synthesis reaction
something that serves no purpose in a chemical reaction
To balance a chemical equation, it may be necessary to adjust the
subscripts on covalent compounds
subscripts on ionic compounds
coefficients
A chemical equation is considered balanced when the
coefficients of the reactants equal the coefficients of the products
same number of each kind of atom appears in the reactants and in the products
products and reactants are the same chemicals
subscripts of the reactants equal the subscripts on the products
What type of change produces a new substance?
chemical
physical
What kind of change would melting be?
physical
chemical
Which set of coefficients correctly balance the equation: __N2H4O2 --> __ N2 + __H2O ?
1 --> 2, 2
2 --> 2, 2
2 --> 1, 1
1 --> 1, 2
What kind of change would burning a hydrogen filled balloon with a match be?
physical
chemical
You spray paint the sidewalk changing it to blue, this is an example of a ___________ change.
physical
chemical
Dissolving NaOH in water.
chemical
physical
Classify the following chemical reaction: 1PbO + 2KI --> 1PbI2 + 1K2O
synthesis reaction
decomposition reaction
single displacement reaction
double displacement reaction
combustion
Products are on what side of the yield sign (-->)?
left
right
In a combustion reaction of a hydrocarbon (CH4) one of the reactants is ________________.
solid carbon (C)
water (H2O)
oxygen gas (O2)
hydrogen gas (H2)
In the following equation, iron (Fe) has been replaced by __________________.
2Al + 3Fe(NO3)2 --> 3Fe + 2Al(NO3)3
nitrate, NO3
water, H2O
aluminum, Al
nitrogen , N
In a double replacement reaction, MgCl2 and Sr(NO3)2 react to produce Mg(NO3)2 and ______.
MgCl2
NaNO3
SrCl2
HCl
What are the products of a combustion reaction?
Hydrogen and Oxygen
Carbon Dioxide and Water
Carbon Dioxide and Oxygen
Water and Hydrogen
What is the balanced chemical equation when Ca reacts with Cu(SO4)?
Ca + Cu2S --> Ca2S + Cu
2Ca + 3CuSO4 --> Ca2(SO4)3 + 3Cu
Ca + CuSO4 --> CaSO4 + Cu
2Ca + Cu2SO4 --> Ca2SO4 + 2Cu
Which of the following reactions does NOT occur based on the activity series.
KCl + Na --> NaCl + K
2Na + ZnF2 --> 2NaF + Zn
Fe + CuCl2 --> FeCl2 + Cu
2HCl + Mg --> MgCl2 + H2
Which of the following is NOT a reason WHY chemical equations must be balanced?
Atoms are neither made nor destroyed, only rearranged in a chemical reaction.
The law of conservation of mass holds true.
The mass of the reactants must equal the mass of the products.
The substance you start with has to be the exact same as the substance you end with.
Which of the following statements is TRUE regarding what is used to balance chemical equations?
If the subscript is changed, the element is changed. (H vs H2)
Changing the subscript changes the identity of the compound. (H2O vs H2O2)
Adjusting the coefficient changes how much of a substance there is, not its identity. (H2 vs 2H2)
You must check the activity series to see if what type of reaction occurs or not?
synthesis
decomposition
single displacement
double displacement
combustion
Which of the following is NOT a diatomic element?
Hydrogen
Chlorine
Carbon
Nitrogen
