Chemical Equations
Measures of Central Tendency
100

True or False.

When balancing a chemical equation, you should only change the stoichiometric coefficients, never the subscripts.

True

100

True or False.

The mean is calculated by finding the average of the numbers in the data set.

True

200

Atoms are neither _____________ nor ____________ during a chemical reaction.

What are created and destroyed?

200

This is the term used for the value found by subtracting 3 from 34 in the below data set.

4, 34, 6, 3, 7, 12

What is the range?

300
These are the starting substances in a chemical reaction.

What are the reactants?

300

Find the mode for the below data set.

25, 31, 16, 25, 20, 33, 16, 7

What are 16 and 25?

400

The below equation is an example of a ___________ reaction.

               A + CB   C + AB

What is a single replacement reaction?

400

True or False.

The median for this data set is 25.

13, 7, 3, 21, 25, 25

False. The mode is 25. 

The median is found by averaging the two middle values when there is an even number of values; the median is 17 [(13 + 21) / 2].

500

Is the below equation a balanced equation? 

            N2 + H2  2 NH3

No. The balanced equation for this reaction is:

       N2  +  3 H  2 NH3

500

What is the mean for the below data set?

3, 7, 4, 1, 5, 1, 7

The mean is 4. 

(3 + 7 + 4 +1 + 5 + 1 + 7) / 7 = 28/7