Answer:
- <u><em>It will be less than 26 °C as water has a relatively higher specific heat than sand.</em></u>
Explanation:
The <em>specific heat </em>of a substance is the amount of heat energy absorbed by one unit of mass of the substance when its temperature increases one unit.
From that, you can derive the equation for the specific heat of a substance:
- specific heat = heat / (mass × ΔT)
Thus, assuming that all the heat provided by the lamp to both samples is the same and, as given, the amount (mass) of both samples is also the same, you have that the specific heat of the samples will be:
- specific heat = constant / ΔT
So, specific heat and ΔT are inversely related.
It is known that water has a higher specific heat than sand (that is why the sand on the shore of a beach is, during the day, hotter than the water and your feet get burned when you walk on a sandy beach on a sunny day).
Then, since the specific heat of water is greater than the specific heat of sand, the increase of temperature of water will be lower and, consequently, water will reach a lower final temperature than sand, when equal amounts of water and sand are heated as described in the experiment. This is the second choice: the final temperature of water is less than 26°C as water has a relatively higher specific heat than water.
Answer : The molal freezing point depression constant of X is 
Explanation : Given,
Mass of urea (solute) = 5.90 g
Mass of X liquid (solvent) = 450.0 g
Molar mass of urea = 60 g/mole
Formula used :
where,
= change in freezing point
= freezing point of solution = 
= freezing point of liquid X= 
i = Van't Hoff factor = 1 (for non-electrolyte)
= molal freezing point depression constant of X = ?
m = molality
Now put all the given values in this formula, we get
![[0.4-(-0.5)]^oC=1\times k_f\times \frac{5.90g\times 1000}{60g/mol\times 450.0g}](https://tex.z-dn.net/?f=%5B0.4-%28-0.5%29%5D%5EoC%3D1%5Ctimes%20k_f%5Ctimes%20%5Cfrac%7B5.90g%5Ctimes%201000%7D%7B60g%2Fmol%5Ctimes%20450.0g%7D)
Therefore, the molal freezing point depression constant of X is
The law of conservation of mass<span> states that </span>mass<span> in an isolated system is neither created nor destroyed by chemical reactions or physical transformations.
</span>
Explanation:
hope it helps you understand moles
Answer:
E
Explanation:
Here in this question, what we will do is to select which of the pairs that do not correlate.
A. Enthalpy and heat content
This two terms are at par with each other. By definition, the enthalpy of a system simply is the total amount of heat content it has.
B. Endothermic reaction and +H
These two terms are at par with each other. An endothermic reaction is one in which heat is absorbed from the surroundings. It has a positive value for the heat content i.e the enthalpy is positive and thus H is positive.
C. Exothermic reaction and -H
An exothermic reaction is one in which heat is released to the environment. It usually has a negative value for the enthalpy and thus the value of H is negative.
D. High energy and High Stability
These two terms are not at par. When an entity has or is of high energy, it is usually unstable. An entity at a higher energy level will not be stable until it goes to a lower level of energy.
Thus higher energy level is associated with lesser stability while lower energy levels are associated with higher stability. The lesser the energy of an entity, the higher its stability.
This makes the option our answer.
