1.) (a) Write the structural formula for 1,3 butadiene.
(b)
Write the balanced equation for the combustion of butadiene.
(c)
Calculate the known ∆Hrx for the combustion of butadiene. (the H value for butadiene
is 111.82 kJ/mole).
(d)
Place the ∆Hrx determined in (c) with the balanced equation in (b)…placing the ∆Hrx on
the proper side of the equation and with correct numeric sign.
You and your esteemed colleague now run an experiment to experimentally determine the
∆Hrx for the combustion of butadiene. You combust 2.7 g of butadiene and the combustion
reaction warms a 5000 g sample of water from 10°C to 15.6°C
(e)
Determine the amount of heat energy gained by the water.
(f)
Determine the amount of heat energy lost by the chemical combusting .
(g)
Determine how many moles of butadiene were combusted
(h)
Determine how much heat is released per mole by the combusting butadiene.
(i)
Rewrite the balanced equation for the combustion reaction here.
(j)
Adjust your answer in (h) such that the amount of heat energy would be appropriate
for the above balanced equation. This is your experimental ∆Hrx. Place this
experimental ∆Hrx with the balanced equation in (i).
(k)
Calculate your % error for the experiment.
2.) Do all of the following;
(a)
Write the structural formula for propyne.
(b)
Write the balanced equation for the combustion of propyne.
(c)
Calculate the known ∆Hrx for the combustion of propyne. (the H value for
propyne is 185.25 kJ/mole).
(d)
Place the ∆Hrx determined in (c) with the balanced equation in (b)…placing the
∆Hrx on the proper side of the equation and with correct numeric sign.
You and your esteemed colleague now run an experiment to experimentally determine the
∆Hrx for the combustion of propyne. You combust 4.0 g of propyne and the combustion
reaction warms a 1000 g sample of water from 20°C to 55°C.
(e)
Determine the amount of heat energy gained by the water.
(f)
Determine the amount of heat energy lost by the chemical combusting .
(g)
Determine how many moles of propyne were combusted
(h)
Determine how much heat is released per mole by the combusting propyne.
(i)
Rewrite the balanced equation for the combustion reaction here.
(j)
Adjust your answer in (h) such that the amount of heat energy would be
appropriate for the above balanced equation. This is your experimental ∆Hrx.
Place this experimental ∆Hrx with the balanced equation in (i).
(k)
Calculate your % error for the experiment.
3.) You and your lab colleague wish to experimentally determine the ∆Hrx for the combustion
reaction of cyclopentane. You combust 50 g of cyclopentane and the combusting pentane
warms a 10,000g sample of water from 20°C to 72°C. (a) determine your experimental
∆Hrx for this reaction. (b) Calculate your % error (the H value for the cyclopentane
molecule is -77.16 kJ/mole.
4.) A 37 gram chunk of copper at 100˚C is dropped into a cup containing 50 grams of water
at 25˚C. the final temperature of the water is 29.8 ˚C. Calculate the specific heat “c”
of copper.