Answer: The half-reactions represents reduction are as follows.
Explanation:
A half-reaction where addition of electrons take place or a reaction where decrease in oxidation state of an element takes place is called reduction-half reaction.
For example, the oxidation state of Cr in
is +6 which is getting converted into +3, that is, decrease in oxidation state is taking place as follows.

Similarly, oxidation state of Mn in
is +7 which is getting converted into +2, that is, decrease in oxidation state is taking place as follows.

Thus, we can conclude that half-reactions represents reduction are as follows.
Answer:
The value of the partial pressure of the oxygen
= 690 torr
Explanation:
Total pressure of the mixture of gases = 736 torr
The partial pressure of water vapor = 46 torr
From the law of pressure we know that
Total pressure = The partial pressure of water vapor + The partial pressure of oxygen 
Put the values of pressures in above equation we get,
⇒ 736 = 46 + 
⇒
= 736 - 46
⇒
= 690 torr
This is the value of the partial pressure of the oxygen.
Argon is a pure element which means that it cannot be broken down further than it already is. Methane, however, is a hydrocarbon, which means it is made out of both hydrogen and carbon and thus can be broken down to separate those elements.
The element bromine is not a reddish-brown liquid. Liquid is the substance bromine.
M=DV
M=3.103 g/mL * 19.8 mL = 61.44 g