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Worksheets7th Grade - Chemical Equations
Total questions: 16
Worksheet time: 11mins
Name
Class
Date
1.
The substances listed on the right side of a chemical equation are the
a)
Yields
b)
Reactants
c)
Products
d)
Precipitates
2.
The substances listed on the left side of a chemical equation are the
a)
Products
b)
Coefficients
c)
Precipitates
d)
Reactants
3.
Identify the reactant(s) and product(s) of the reaction.
a)
All three are reactants and none are products.
b)
Hydrogen and water are the reactants, and oxygen is the product.
c)
Water and oxygen are the reactants, and hydrogen is the product.
d)
Hydrogen and oxygen are the reactants, and water is the product.
4.
A molecule is smaller than an atom.
a)
True
b)
False
5.
How many Oxygen (O) atoms are in 2C2HO8Cl2
a)
2
b)
16
c)
8
d)
5
6.
How many Hydrogen (H) atoms are in NH3O5
a)
3
b)
4
c)
5
d)
1
7.
A molecule is________
a)
a glob of gelatinous goo
b)
smaller than an atom
c)
filled with raisons
d)
more than one atom bonded together
8.
How many molecules of Carbon are in the following formula? 3C2H6
a)
3
b)
6
c)
12
d)
18
9.
How many elements are in C6H12O6?
a)
1
b)
2
c)
3
d)
4
10.
Identify the Reactants in this equation.
a)
A
b)
B
11.
Fill in the blank:
The law of conservation of mass states that matter cannot be created nor __________________.
The law of conservation of mass states that matter cannot be created nor __________________.
a)
destroyed
b)
rearranged
c)
transferred
d)
changed
12.
In a closed system, a chemical reaction takes place. The mass of the reactants in the beginning of the reaction is 25g. What does the mass have to be in the end of the reaction in order to follow the law of conservation of mass?
a)
25g
b)
You can't tell with the given information.
c)
30g
d)
15g
13.
In a reaction A + B ----> C, reactant A has 5g and product C has 9g. How many grams does reactant B should have?
a)
4g
b)
5g
c)
9g
d)
14g
14.
If reaction starts with 20g of reactants it should produce
a)
a total of 40g of products
b)
a total of 10g of products
c)
a total of 80 g of products
d)
a total of 20g of products
15.
Students react baking soda & vinegar.
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?
Which of the following would provide the evidence that the number of atoms present before a chemical reaction is equal to the number of atoms present after the chemical reaction?
a)
The mass of the plastic bag, baking soda, and vinegar before the reaction was equal to the mass after the reaction.
b)
Bubbles were produced during the reaction, which meant that a gas was being produced.
c)
The plastic bag did not change in any way, indicating that it was not involved in the reaction.
d)
The mass of the baking soda was exactly equal to the mass of the vinegar used to create the chemical reaction.
16.
Suppose a reaction were to happen in an open container in a lab. During the reaction, the scientist observes the chemicals bubble, and produce a gas. During the analysis the scientist notices that the reactants weighed 20 g when he started, and the product weighed 18 g. Explain what happened.
a)
His chemical reaction defied the law of conservation of mass
b)
The product destroyed mass during the reaction
c)
The reactants created matter during the reaction
d)
The gas that was produced was not able to be weighed since the container was open.
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