Answer:
A. releases a large amount of heat
Explanation:
A reaction is said to be spontaneous if it can proceed on its own without the addition of external energy. A spontaneous reaction is not determined by the length of time, because some spontaneous reactions are completed after a long period of time. They are exothermic in nature. An example is the conversion of graphite to carbon which takes a long period of time to complete. Spontaneous reactions are known to increase entropy in a system. Entropy is the rate of disorder in a system.
In the combustion of fire, energy is released to the surroundings as there is a decrease in energy. This is an example of a spontaneous reaction because it is an exothermic reaction, which causes an increase in entropy and a decrease in energy.
Answer:
[HOCH₂CH₂OH] = 24.1 m
Explanation:
Ethylene glycol → HOCH₂CH₂OH
60% by mass means that 60 g of ethylene glycol are contained in 100 g of solution.
Solution mass = Solute mass + Solvent mass
100 g = 60 g + Solvent mass
Solvent mass = 40 g
Molality are the moles of solute contained in 1kg of solvent.
We determine the moles of solute → 60 g . 1mol/62 g = 0.967 moles
We convert the mass of solvent from g to kg → 40 g . 1kg/1000 g = 0.04 kg
Molality → 0.967 mol / 0.04 kg = 24.1 m
The given molarity of sodium hydroxide solution = 2.0 M
The required concentration of sodium hydroxide is 65 mL of 0.6 M NaOH
Converting 65 mL to L:
Calculating the moles of NaOH in the final solution:
Finding out the volume of 2.0 M solution taken to prepare the final solution:
Therefore, 19.5 mL of 2.0 M NaOH solution and make it up to 65 mL to prepare 0.6 M NaOH solution.
The name for NH3 is Nitrogen trihydride.
hey there!:
A) Knowing theatre the protease is showing the highest activity at pH 4-6, implies that the amino acid that amino acid that it is acting in is an amino acid with a basic side chain. Therefore, the residues can be any one of the three basic amino acids being histidine, arginine or lysine , having basic side chains at neutral pH.
b) The mechanism of reaction of cysteine proteases is as follows:
First step in the reaction is the deprotonation of a thiol in the cysteine proteases's active site by an adjacent amino acid with a basic side chain, which might be a histidine residue. This is followed by a nucleophilic attack by the anionic sulfur of the deprotonated cysteine on the substrate carbonyl carbon.
Here, a part of the substrate is released with an amine terminus, restoring the His into a deprotonated form, thus forming a thioester intermediate, forming a link between the carboxy-terminal of the substrate and cysteine, resulting in thiol formation. Thus the name thiol proteases. The thioester bond is then hydrolyzed into a carboxylic acid moiety while again forming the free enzyme.
C) cysteine proteases have a pka of 8-9 but when they are deprotonated by a His residue, their pka would come down to 6-8, which would be their optimal pH for functioning. This is because there is a deprotonation of the thiol group , later restoring the HIS deprotonated form and then formation of a thioester bond. This thioester bond when hydrolysed will a carboxylate moeity , which is responsible for bringing the pH down towards a more acidic side.
d) at the optimal pH , the fraction of deprotonated cysteine and protonated B will be equal which will change with the change in pH.
Hope this helps!
