Answer: Option (a) is the correct answer.
Explanation:
Entropy means the degree of randomness present within the molecules of an object.
When a substance is present in a solid state then its molecules are held together because of strong intermolecular forces of attraction.
As a result, molecules are not able to move freely and therefore, there will be no randomness.
But when a substance changes into liquid state then its molecules mover further apart from each other due to gain in kinetic energy. Hence, randomness increases.
On the other hand, when a substance moves from liquid to gaseous state then its molecules gain more kinetic energy due to which there will be high degree of randomness.
Therefore, as the products in the given reaction are present in liquid and gaseous state. So, this means that there has been an increase in entropy.
A decrease in entropy is represented by negative sign and an increase in entropy is represented by a positive sign.
Thus, we can conclude that the sign of 
for the given reaction is > 0.
Answer:
Explanation:
Given parameters:
Number of given calories = 614 cal
Note that 1cal = 4.18J
Now to convert the given calories to joule, we use the relationship below:
Since 1Cal gives 4.18Joule of energy
614Cal will produce 4.18 x 614;
2566.52J of energy.
This written as 2.57 x 10³J because it has three significant numbers of 2, 5 and 7.
In writing an operation that involves deducing the significant numbers, we simply express our answer to that shows the lowest number of significant numbers. Our problem has 3 significant numbers each and the answer is given in that regard.
The answer is D: 400N
your welcome
Answer:
q = -6464.9 kJ
Explanation:
We are given that the heat of combustion is ∆H° = −394 kJ per mol of carbon.Therefore what we need to do is calculate how many moles of C are in the lump of coal by finding its mass since the density is given.
vol = 5.6 cm x 5.1 cm x 4.6 cm = 131.38 cm³
m = d x v = 1.5 g/cm³ x 131.38 cm³ = 197.06 g
mol C = m/MW = 197.06 g/ 12.01g/mol = 16.41 mol
q = −394 kJ /mol C x 16.41 mol C = -6464.9 kJ
