00:01
Hello students, in this question we are asked to determine delta r u for the combustion of stearic acid.
00:09
Solution is according to calorimetry problem, we have delta h reaction is equal to q reaction is equal to minus q calorimeter which is equal to minus m c s into delta t.
00:44
So, we have the data is given in the question just plugging the values minus 0 .7081 into 10 .066 into 2 .632.
01:01
So, this is equal to minus 18 .76 kilo joule per mole.
01:10
So, now we have the formula delta h is equal to delta u plus n into r t which implies delta h minus n here delta is there delta n r t is equal to delta u.
01:35
Now, here n is equal to 0 .7081 that is mass divided by molar mass 284 .4 a that is of stearic acid given in the question.
01:51
So, this equals 0 .0025 delta t is equal to 2 .632 plus 273.
02:06
So, this is equal to 275 .632...