Answer:
+4
Explanation:
Hello,
In this case, considering nitrogen dioxide's formula:
And due to the fact that oxygen's oxidation state is -2 in this case, we could find nitrogen's oxidation state in nitrogen dioxide by using a balance charge:
For that reason, nitrogen's oxidation state is +4:
Best regards.
Answer:
Chloroform is expected to boil at 333 K (60 ).
Explanation:
For liquid-vapor equilibrium at 1 atm, = 0.
We know, , where T is temperature in kelvin scale.
Here both and
are corresponding to vaporization process therefore T represents boiling point of chloroform.
So,
or, T = 333 K
So, at 333 K (60 ) , chloroform is expected to boil.
Answer:
Use a 10 mL pipet and a 50 mL volumetric flask, <em>twice</em>
Explanation:
Given those conditions, in order to have a solution that is 25 times less concentrated that the one previously prepared, we would need two dillution steps, as suggested by the problem.
If we take an aliquot of 10 mL and dilute it to a final volume of 50 mL, we prepare a solution that is 5 times less concentrated. And if we then take again an aliquot of 10 mL of that dilluted solution and dilute it to a final volume of 50 mL, we would have a solution 25 (5 times 5) times less concentrated than the original one.
In order to verify, we can calculate the resulting concentration and compare it with the original one:
Thus we can see that the obtained concentration is in fact 25 times lower than the original concentration.