The correct answer of the given question above would be option B. IRON 0.449. Based on the given details above about an unknown substance that has a mass of 14.7 g and the substance absorbs 1.323×102 J of heat, the temperature of the substance is raised from 25.0 ∘C to45.0 ∘C, most likely, the substance is IRON. Hope this answers the question.
Answer:
A 0.001 molar solution of weak acid has a pH = 4.0,The pKa is :
B. 5
Explanation:
pH = It is negative logarithm of hydrogen ion concentration.
pH = -log([H+])
Ka = It is the dissociation constant.
pKa = -log(Ka)
<u>The acid dissociates according to the equation given below:</u>
Here , The concentration of A- and H+ will be same
So,
[H+] = [A-].....(1)
Now ,
pH = 4.0
pH = -log([H+])
4.0 = -log([H+])
- 4.0 = log([H+]) take antilog both side::"use scientific calculator"
From equation (1), [A-] =
[HA] = 0.001 M (given)
Insert the value of HA , H+ and A- in Ka
pKa = -log(Ka)
pKa = 5
There are several reasons behind why they must keep accurate notes.
There may be a mistake or an anomaly that occurs during the process, and something completely different than the desired compound may be created and the process may need to be repeated.
The investigation may be successful and may need to be repeated.
The investigator may need to prove that the project was done by him and the notes may help him to do so. (hence why they must be dated and signed.)
The investigator may need them to protect him from legal action.
The pharmaceutical company may need proof that the possible medicine is safe and effective, and that it works as it should.
the name of the fourth dog is:
what lol so tricky
Answer:
Process B : constant pressure condition
Process A : constant volume condition
Explanation:
In case of constant pressure, some of the energy is used to do work on the surrounding to keep pressure constant. Due to this, the total heat energy is less than in case of constant volume. In Case of constant Volume all of heat is available, produced in reaction because no work is done.
If we look at our data,we will find that process B has energy 23.3 KJ which is less than process A, the energy of which is 25.9 KJ. It means Process B is occurred at constant pressure condition and Process A has occurred at constant volume condition