The chemical reaction would be written as:
2HgO = 2Hg + O2
We use this reaction and the amount of the reactant to calculate for the moles of oxygen produced. THen, we use avogadro's number to convert it to molecules. We do as follows:
12.5 g HgO (1 mol / 216.59 g) (1 mol O2 / 2 mol HgO) ( 6.022x10^23 molecules O2 / 1 mol O2 ) = 1.74x10^22 molecules O2 produced
You will have divided 50200 by 1000000 which 0.0502
Answer:
Final temperature of the gas is 576
.
Explanation:
As the amount of gas and pressure of the gas remains constant therefore in accordance with Charles's law:

where
and
are volume of gas at
and
temperature (in kelvin scale) respectively.
Here
,
and 
So
849 K = (849-273)
= 576 
So final temperature of the gas is 576
.
Well, first of all, the formula for finding potential energy is;
PE=mgh
Where; m is the mass
g is the gravitational force or acceleration due to gravity
h is the height.
Anyway, according to the question, the mass is 1kg, the acceleration due to gravity has a constant value of 10ms² . And the height is 3m. Now you just have to use all these in the formula. So;
mgh= 1 x 10 x 3. That will be 30. And the unit of potential energy is Joule. So the answer is 30 joules. Hope i helped. Have a nice day.