A student sets up the following equation to solve a problem in solution stoichiometry.
(The ? stands for a number the student is going to calculate.)
Enter the units of the student's answer.
[tex]\frac{(0.27 L)\left(\frac{1 mL}{10^{-3} L}\right)\left(2.07 \frac{g}{mL}\right)}{\left(20.15 \frac{g}{mol}\right)}=? \square[/tex]
Answer (2)
The units of the student's answer from the stoichiometry equation are mol. By simplifying the units through cancellation of common terms, we find that the final unit is moles (mol). Understanding how these units work is crucial in stoichiometric calculations in chemistry.
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Write down all the units in the expression.
Simplify the units by cancelling out common units in the numerator and denominator.
The remaining units will be the units of the answer.
The units of the answer are m o l .
Explanation
Analyze the problem We are given an equation and asked to find the units of the answer. The equation is: ( 20.15 m o l g ) ( 0.27 L ) ( 1 0 − 3 L 1 m L ) ( 2.07 m L g ) = ? We need to simplify the units to find the units of the answer.
Simplify the units Let's write down all the units in the expression: m o l g L × L m L × m L g Now, we can cancel out the common units in the numerator and the denominator. We have L in the numerator and L in the denominator, so they cancel out. We also have m L in the numerator and m L in the denominator, so they cancel out. We also have g in the numerator and g in the denominator, so they cancel out. This leaves us with: m o l 1 1 Which simplifies to m o l .
State the final answer Therefore, the units of the answer are m o l .
Examples
In chemistry, stoichiometry is used to calculate the amounts of reactants and products involved in chemical reactions. For example, if you are performing a titration, you need to know the number of moles of the titrant required to react completely with the analyte. By understanding the units and how they cancel out in stoichiometric calculations, you can accurately determine the amount of a substance in a sample. This is crucial in fields like pharmaceutical research, environmental monitoring, and quality control in manufacturing.
