Answer : The correct option is, (E) 7.8 atm
Explanation :
The partial pressure of
= 8.00 atm
The partial pressure of
= 5.00 atm
= 0.0025
The balanced equilibrium reaction is,

Initial pressure 8.00 5.00 0
At eqm. (8.00-x) (5.00-x) 2x
The expression of equilibrium constant
for the reaction will be:

Now put all the values in this expression, we get :

By solving the terms, we get:

The equilibrium partial pressure of
= (8.00 - x) = (8.00 - 0.15) = 7.8 atm
Therefore, the equilibrium partial pressure of
is 7.8 atm.
Methanol is the substance that can be broken down by chemical means, the remaining ones are elements.
Answer:
a) Measurements have a good precision.
Explanation:
Accuracy is the proximity of the data to the value considered as real, in this situation we do not know the real value and we do not know if the data is accurate or not, so we can discard options b and d.
Now, precision is the proximity of the data obtained among themselves and that is what we can observe, so the appropriate answer is the option a.
It would be 0.341 because if you add 0.229 and 0.112 it will be 0.341
Answer:

Explanation:
Given that:
The Half-life of
=
is less than that of 
Although we are not given any value about the present weight of
.
So, consider the present weight in the percentage of
to be y%
Then, the time elapsed to get the present weight of
= 
Therefore;

here;
= Number of radioactive atoms relating to the weight of y of 
Thus:

--- (1)
However, Suppose the time elapsed from the initial stage to arrive at the weight of the percentage of
to be = 
Then:
---- (2)
here;
= Number of radioactive atoms of
relating to 3.0 a/o weight
Now, equating equation (1) and (2) together, we have:

replacing the half-life of
=
( since
)
∴

The time elapsed signifies how long the isotopic abundance of 235U equal to 3.0 a/o
Thus, The time elapsed is 