Question 15 4 out of 4 points starting with 156 g of

 Question 15
4 out of 4 points
Starting with 1.56 g of salicylic acid, a student prepares 1.75 g of aspirin. If the
calculated mass of aspirin is 1.88 g, what is the percent yield?
Selected Answer:
93.1%
Answers: 121%
93.1%
89.1%
107%
83.0%
Response
Feedback:
Percent yield = Actual yield x 100% = 1.75 g x 100% =
93.1% Theoretical Yield 1.88 g
 Question 16
4 out of 4 points
Considering the limiting reactant concept, how many moles of copper(I) sulfide are
produced from the reaction of 1.00 mol of copper and 1.00 mol of sulfur?

2 Cu( s ) + S( s ) Cu
2
S( s )
S
 Question 17
0 out of 4 points
What is the mass of silver metal produced from 6.35 g of copper? (You must balance
the equation first)
__Cu( s ) + __AgNO
3
( aq ) → __Cu(NO
3
)
2
( aq ) + __Ag( s )

=
 Question 18
0 out of 4 points
What volume of oxygen gas reacts with 20.0 mL of hydrogen chloride? (Assume
temperature and pressure remain constant.)
(You must balance the equation first)
__ HCl( g ) + __O
2
( g ) __Cl
2
( g ) + __H
2
O( g )
2

 Question 19
4 out of 4 points
How many moles of hydrogen gas are produced from 0.500 mol of water? (You must
balance the equation first)
__Ca( s ) + __H
2
O( l ) → __Ca(OH)
2
( aq ) + __H
2
( g )
Selected Answer:
0.250 mol
Answers:
0.250 mol
0.500 mol
1.00 mol
2.00 mol
none of the above
Response Feedback: Ca( s ) +2 H
2
O( l ) → Ca(OH)
2
( aq ) + H
2
( g )
? mol H
2
= 0.500 mol H
2
O x 1 mol H
2
= 0.250 mol H
2
2 mol H
2
O
 Question 20
4 out of 4 points
What is the predicted product from the following combination reaction?
Sr( s ) + Br
2
( l )
2