1. QUESTION:
Consider the reaction: N2 + 3 H2  2 NH3 Suppose mol of N2 is used up in this reaction. How much NH3 is produced?
A g, B g, C g
Consider the reaction: N2 + 3 H2  2 NH3 Suppose a reaction mixture initially contained mol N2, and now contains only mol N2 as a result of the reaction, how much H3 was consumed?
A mol, B mol, C mol
PAUSE
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2. QUESTION:
Consider the reaction: N2 + 3 H2  2 NH3 Suppose mol of N2 is used up in this reaction. How much NH3 is produced?
A g, B g, C g
17.03 g NH3
2 mol NH3
0.500 mol N2 x x
1 mol N2
1 mol NH3
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We’re given that the amount of nitrogen consumed in the reaction is moles.
To calculate the amount of ammonia produced, all we have to do is multiply
the moles of nitrogen consumed by a conversion factor.
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We use the coefficients in the balanced equation to construct our conversion factor.
Since we’re interested in ammonia, we put the coefficient of ammonia in the numerator
CLICK The coefficient of ammonia in the balanced equation is 2.
HIGHLIGHT 2 in balanced equation and 2 in numerator
... and put the coefficient of nitrogen in the denominator
CLICK The coefficient of N2 in the balanced equation is 1.
HIGHLIGHT 1 in balanced equation and 1 in denominator
The ratio of coefficients serves as a conversion factor.
SHOW CANCELLATION OF UNITS
An the answer we get here is 1.00 moles of ammonia.
CALLOUT “= 1.00 mol NH3”
But the choices given to us are in grams.
So we need to convert our answer to grams
By now, you should know how to do this.
We multiply moles of ammonia by
CLICK CLICK the molar mass of ammonia
Carrying out the calculation gives an answer of 17.0 grams.
Note that we keep three significant digits in our answer since the least precise term in our calculation, 0.500,
has only three significant digits. The numbers 2 and 1 in the conversion factors are exact, while the molar
mass has four significant digits.
Therefore, the correct answer is C.
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= g NH3

3. Video ID: © 2008, Project VALUE (Video Assessment Library for Undergraduate Education), Department of Physical Sciences Nicholls State University Author: Glenn V. Lo Narrator: Funded by Louisiana Board of Regents Contract No. LA-DL-SELECT-13-07/08