WorksheetsChemical Reactions Review
Total questions: 25
Worksheet time: 56mins
The three (3) indicates which part of the equation?
reactants
products
equation
formulas
What is a whole number that appears in front of a formula in a balanced chemical equation?
subscript
reactant
coefficient
product
Hydrogen and oxygen chemically combine to produce water. What state of matter will oxygen be in the equation?
gas
liquid
solid
aqueous
When balancing chemical equations, you can only change what?
subscripts
formulas
coefficients
products
CH4 + __O2 --> CO2 + H2O
What will the coefficient of the O2 be after balancing the equation?
1
2
3
4
__CH4 + __O2 --> __CO2 + __H2O
What coefficients will balance the equation?
1,1,1,1
2,1,2,1
1,4,1,2
1,2,1,2
__H2 + __O2 --> __H2O
What will the coefficient of the H2O be after balancing the equation?
1
2
3
4
NaBr + CaF2 --> NaF + CaBr2
What are the coefficients for the balanced equation?
2,1,2,1
1,2,1,2
2,0,2,0
4,2,4,2
PbCl2 + AgNO3 → Pb(NO3)2 + AgCl
3Ca + 2AlCl3 --> 3CaCl2 + 2Al
is what type of reaction?
2Pb(NO3)2 --> 2PbO + 4NO2 + O2
is what type of reaction?
Synthesis
Decomposition
Single Displacement
Combustion
If an element is diatomic it should have a subscript of___
1, always
2, only when it is an element
it shouldn't have a subscript, it should have a coefficent
2, when bonded in a compound
How many atoms are there TOTAL in H2SO4 ?
6
5
7
3
How many Nitrogen atoms are in (NH₄)₂CrO₄?
1
2
8
16
How many Hydrogen atoms in 3(NH₄)₂CrO₄?
4
2
8
24
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
New problem: If 3.5 moles of oxygen gas are used up as ethane combusts completely, how many moles of carbon dioxide are produced?
0.5 mol CO2
0.57 mol CO2
2.0 mol CO2
3.0 mol CO2
3.5 mol CO2
What is a mole ratio?
An animal that burrows underground.
How many moles of reactant are used up in a chemical reaction.
The ratio of a reactant / product to a different one - compared by the number of particles.
The process by which we multiply fractions by using numbers from a chemistry problem.
Where are the numbers for a mole ratio found?
They are part of the chemical formulas for the reactants / products.
They are given in the problem.
They are found on the periodic table for those elements.
They are found as coefficients in the reaction's balanced chemical equation.
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
New problem: If 16 moles of carbon dioxide are formed by this reaction, how many moles of water were also produced?
4 mol H2O
6 mol H2O
24 mol H2O
96 mol H2O
384 mol H2O
2 C2H6 + 7 O2 → 4 CO2 + 6 H2O
New problem: How many moles of ethane (C2H6) are required to produce 13.5 moles of water from the above reaction?
4.5 mol C2H6
27 mol C2H6
40.5 mol C2H6
81 mol C2H6
162 mol C2H6
How many atoms of each element in the REACTANTS?
2H3PO4 + 3Mg(OH)2 --> Mg3(PO4)2 + 6H2O
3
Mg
2
P
14
O
12
H
What is wrong with how this student balanced the equation?
Original equation: Ag + O2 ---> Ag2O
Solution: Ag + O2 ---> 2Ag2O
They changed the molecular structure of the products/reactants.
The silver (Ag) still isn't balanced.
The oxygen (O) still isn't balanced.
They left out the reactants.
Balance this equation.
__Mg + __Cl2 --> __MgCl2
1, 2,1
already balanced
2,1,1
1,1,2
Balance this equation
__Zn +__HCl-->__ZnCl2 +__H2
1,1,2,1
1,1,1,2
1,2,1,1
2,1,1,1
