Answer: first option, the work output of the hairdryer will be less than the work input.
Explanation:
1) The work output measured in watts is the power of hair dryer measured in joules per second.
2) The hair dryer converts electrical energy from the wall outlet to mechanical and thermal energy: hot wind.
3) Nevertheless, you can never expect a 100% efficiency of the machines: due to friction, some energy is converted into useless energy.
So, efiiviency = power output / power input< 1 ⇒
power output = work output / time
input power = work input / time
⇒ work output / work input < 1
⇒ work output < work input.
Which is the first option: the work output of the hairdryer will be less than the work input
I’m pretty one of the answers is water, but I don’t know if there is more
Answer:
Only gives spontaneous reaction.
Explanation:
A redox reaction will be spontaneous if standard reduction potential () of the reaction is positive. Because it leads to negative standard gibbs free energy change (), which is a thermodynamic condition for spontaneity of a reaction.
Where and represents standard reduction potential of reduction half cell and standard reduction potential of oxidation half cell.
(1) Oxidation: ;
Reduction: ;
So,
Hence this pair will give spontaneous reaction.
(2) Similarly as above,
Hence this pair will give non-spontaneous reaction.
(3) Similarly as above,
Hence this pair will give non-spontaneous reaction.
(4) Similarly as above,
Hence this pair will give non-spontaneous reaction.