Answer:
ΔH = -976.5 kJ
Explanation:
For the reaction given, there are 2 moles of benzene (C6H6). The heat of this reaction is -6278 kJ, which means that the combustion of 2 moles of benzene will lose 6278 kJ of heat. It is an exothermic reaction.
The value of ΔH, the enthalpy, is a way of measurement of the heat, and it depends on the quantity of the matter (number of moles).
So, 24.3 g of benzene has :
n = mass/ molar mass
n = 24.3/78.11
n = 0.311 moles
2 moles ------------ -6278 kJ
0.311 moles ----------- x
By a simple direct three rule:
2x = -1953.08
x = -976.5 kJ
Answer:
306.6g/mol
Explanation:
To calculate molecular weight you need to know how many grams ou have in a determined amount of moles of substance. As you have the mass of the sample (1.42g), you need to find how many moles are, as follows:
The reaction of the acid HX with the base YOH is:
HX + YOH → H₂O + YX
<em>1 mole of acid reacts per mole of base.</em>
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In a titration, the solution turned pink when moles base = moles acid.
Moles of base that the student added (Using the volume and molarity of the solution) are:
32.48mL = 0.03248L ₓ (0.1426 moles base / L) = 0.004632 moles of base
As the titration is in equivalence point, there are 0.004632 moles of the acid
Molecular weight (Ratio between grams of sample and its moles) is:
1.42g / 0.004632 moles =
<h3>306.6g/mol</h3>
An isotope is when a normal atom has too many neutrons and its weight has been offset.
The amount of gravitational potential energy an object has depends on its height and mass. The heavier the object and the higher it is above the ground, the more gravitational potential energy it holds. Gravitational potential energy increases as weight and height increases.
I looked this up but hope it helps!