0:02 the other kind of calorimetry problem
0:04 that you will encounter is what we do
0:07 with a bomb calorimeter so typically the
0:09 words in the problem will say bomb
0:12 calorimeter in it so just remember it's
0:14 that sealed vessel that has all the
0:17 other um materials in there and the big
0:19 thing in there with a bomb calorimeter
0:22 you should have a Capital C which is the
0:25 heat capacity of the bomb
0:28 calorimeter so that should be somewhere
0:31 in the problem on here so what we're
0:34 doing in here is we are taking this mass
0:36 of glucose and we're burning it inside
0:39 of a bomb calorimeter so we are com uh
0:42 performing a combustion reaction so in a
0:44 combustion reaction it should be
0:46 exothermic so we should be releasing
0:48 heat the temperature of the calorimeter
0:55 increased from 23.8 De C to 35.6 De C
1:00 and then the calorimeter contains 775 G
1:03 of water and the bomb itself so here's
1:06 the key it has a heat capacity and look
1:10 at the units there 893 jewles per
1:12 degrees celsus so we know we have a
1:15 Capital C on here and now the question
1:17 is how much heat was produced by the
1:20 combustion of the glucose sample so we
1:23 need to go ahead remember the sum of all
1:26 the cubes are going to equal zero so
1:29 then we have to ask ourselves what are
1:30 the cues
1:33 that are in the problem so the Q in
1:35 there we have our Q the reaction and
1:37 that's the
1:39 combustion of the glucose so there's a
1:43 combustion that's happening there plus
1:46 we know that we have water in the
1:48 calorimeter plus there's going to be a
1:51 CU of the water because there's going to
1:53 be some heat transfer of the water
1:56 itself and then it tells us the bomb has
1:59 some sort of heat capacity so then
2:00 there's a
2:02 of the
2:05 calorimeter we're going to add all those
2:08 up to be zero so if we go back to what
2:09 is the system and what are the
2:12 surroundings this PE the reaction is
2:13 what we're
2:16 interested so that's our system
2:22 surroundings but I like to break it up
2:25 into the separate cues so we don't know
2:28 what our Q of the reaction is we can
2:33 calculate the Q of our water as the M
2:37 lowercase uh C delta T so that's our
2:39 Mass specific heat capacity and our
2:41 change in temperature and then we are
2:44 also told what the heat capacity of our
2:48 calorimeter is times delta T so our
2:51 change in temperature and how that will
2:53 all equal zero so this is what we want
2:56 to calculate we know that we have our
3:03 mass of our water is 700 75 G our c is
3:08 4.184 Jew per degrees Celsius G or
3:10 you'll see GRS per degree celsius and
3:14 our change in temperature is going to be
3:19 35.6 minus 23.8 Dees
3:23 C our Capital C on here is given to us as
3:24 as
3:28 893 jewles per de Cs and then we're
3:31 going to multiply that by our same
3:34 temperature final initial so our delta T
3:40 is 35.6 minus 23.8 degrees cus on here
3:42 so we can go ahead and calculate this
3:45 out our Q the reaction if we end up
3:47 calculating all of this out we should
3:58 38,000 300 jewles we calculate this out
4:00 over here
4:02 um and we should have
4:05 10,500 Jews we set that equal to zero so
4:08 we go ahead and add this up our Q of the
4:11 reaction plus
4:16 48,800 Jew equal 0 and then our Q of the
4:20 reaction should equal -
4:24 48,800 Jew and that should make sense to
4:27 us because we have a negative number we
4:37 reaction so we have a negative value it
4:40 makes sense in terms of the combustion
4:43 of our glucose and a lot of times what
4:45 we will do is we will actually uh report
4:47 these values in kilog so make sure you
4:50 look at your answer to see what units
4:52 you're going to use because you may have
4:56 to convert this as -
4:59 4880 jewles you might have to convert in k
5:00 k
5:04 there's one k for every 1,000 jewles I
5:07 never skip writing these dimensional
5:10 analyses so you will get a final number
5:11 of minus
5:15 48.8 K so you'll have to look at your
5:18 problem to see which value uh you might
5:21 be calculating whether it is kles or jewels
