Answer : The final pressure of the gas is, 
Explanation :
Boyle's Law : It is defined as the pressure of the gas is inversely proportional to the volume of the gas at constant temperature and number of moles.

or,

where,
= initial pressure = 545 mmHg
= final pressure = ?
= initial volume = 775 mL
= second volume = 171 mL
Now put all the given values in the above equation, we get:


Therefore, the final pressure of the gas is, 
Unfortunately, your question is incomplete So, according to the attached picture of the complete question we will explain the answer:
according to the reaction equation:
C(s) + 2H2(g) ↔ CH4(g) ΔH° = -74.6KJ
So the true answer will be
D i and ii
- as by adding more C and it is a reactant so the reaction will go rightward to the product to decrease the C to achieve the equilibrium again, the movement of the reaction towards the products will make the CH4 increase
- and by decreasing the Heat and the heat here is as a product as the reaction is exothermic so by decreasing the heat the reaction will go toward the products to increase the heat and achieve the equilibrium again, and that also makes the CH4 increase as it is a product.
So the true answer is
D i and ii as the attached photo
When potassium is added to water the metal melts and floats. It moves around very quickly in the surface of the water.
<span>When the unknown liquid is heated and turned into vapor, it will not occupy the entire container. The volume in the molar mass (nRT)/PV will be greater than the actually volume of the unknown, and the calculated molar mass will be less than the actual molar mass.</span>
The correct answer should be A