A buffer is usually composed of either:
- a weak base combined with its conjugate acid, or
- a weak acid combined with its conjugate base
Now, examining each of the choices:
1- KOH and NH3: since they are both bases, thus this mixture is not a buffer
2- HBr and NaCl: since HBr is a strong acid while NaCl is the salt of another different acid, thus this mixture is not a buffer
3- HCl and HBr: these are both considered to be strong acid, thus this mixture is not a buffer
4- HCHO2 and NaCHO2: as for HCH02, it is considered a weak base while NaCHO2 is considered its conjugate base, thus this mixture is a buffer
I haven't got the answer but I'm probably sure that u can actually look up that answer hoped it help
<u>Answer: </u>The correct answer is Option B.
<u>Explanation:</u>
First law of thermodynamics states that the energy can neither be destroyed not be formed but it can only be transformed from one form to another.
Here, the internal energy of the system is being transformed to the heat energy and the work done by the system. The equation used to represent first law of thermodynamic is:
where,
represents the internal energy of the system.
Q = heat released or absorbed by the system.
w = work done by or on the system.
Hence, the correct answer is Option B.
