Answer:
Heat lost by the pancake = Heat gained by butter
Explanation:
Because energy is always conserved, this process involves the loss of energy by one substance which is gained by another.
The pancakes were freshly made, so they are hot; having the required energy to melt the butter placed on them. The butter absorbs heat from the pancakes which is equal to or greater than its melting point. Thus, the butter melts due to the heat absorbed.
Therefore,
Heat lost by the pancakes = Heat gained by butter
Answer:
Two characteristics that make water a good choice for the recrystallization solvent for benzoic acid are
- Low solubility for benzoic acid at room temperature
- Less expensive
Explanation:
Characteristics of a Good Recrystallization Solvent:
- Cheap.
- High volatility.
- No reaction with substrate to be made pure.
- Insoluble impurities should not be dissolced by the olvent at all temperatures.
- At room temperature the solvent should have high solubility for soluble impurities well
- At room temperature the substance to be purified should be insoluble in the solvent.
As such water has both low solubility for benzoic acid at room temperature and water is cheap or readily available
Answer:
The answer is A. Polar covalent; negatively
Explanation:
Hydrogen bonds form between molecules containing polar covalent bond the hydrogen bond is been a hydrogen atom of one molecule and a partially negative charged atom of another.
Example 
(water):- It contain a slight positive charge on one side and a slight negative charge on the other.
where, E^{o} (Ag+/Ag) = std. reduction potential of Ag+ = 0.7994 v
and Sn2+/Sn = std. reduction potential of Sn2+ = -0.14 v
Thus, E^{o}cell = 0.7994v - (-0.14v) = 0.9394 v
Now, ΔG^{o} = -nF
,
where, n = number of electrons = 2
F = Faraday's constant = 96500 C
∴ΔG^{o} = 2 X 96500 X 0.9394 = -1.18 X
Now, using Nernst's Equation we have,
![[tex]E_{cell} = 0.9394 - \frac{2.303X298}{2X96500}log \frac{0.0115}{ 3.5^{2} }](https://tex.z-dn.net/?f=%20%5Btex%5DE_%7Bcell%7D%20%3D%200.9394%20-%20%5Cfrac%7B2.303X298%7D%7B2X96500%7Dlog%20%5Cfrac%7B0.0115%7D%7B%203.5%5E%7B2%7D%20%7D%20)
E_{cell} = 0.9765 v
Finally, ΔG = -nFE = -2 X 96500 X 0.9765 = -1.88 X
