Answer : The value of new volume is, 50.0 mL
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 at STP = 1 atm
= final pressure = 4.00 atm
= initial volume at STP = 200.0 mL
= final volume = ?
Now put all the given values in the above equation, we get:


Therefore, the value of new volume is, 50.0 mL
Mezoic era began 252m years ago and ended 6.6m years ago.
It was a time of geological and biological transition. During this era the continents began to drift to their present configuration.
3 of the largest mass extinction occurred at this era. One which include the dinosaurs.
I hope this helped. :)
Moles are the division of the mass and the molar mass. The moles of mercury (ii) oxide in the decomposition reaction needed to produce oxygen are 0.781 moles.
<h3>What is a decomposition reaction?</h3>
A decomposition reaction is a breakdown of the reactant into simpler products. The decomposition of mercury (ii) oxide can be shown as:
2HgO(s) → 2Hg(l) + O₂(g)
From the reaction, it can be said that 2 moles of mercury (ii) oxide decomposes to produce 1 mole of oxygen.
The moles of oxygen that needs to be produced are calculated as:
Moles = mass ÷ molar mass
= 12.5 gm ÷ 32 gm/mol
= 0.39 moles
0.39 moles of oxygen are needed to be produced.
From the stoichiometric coefficient of the reaction, the moles of HgO is calculated as: 2 × 0.39 = 0.781 moles
Therefore, 0.781 moles of HgO are required in the reaction.
Learn more about moles here:
brainly.com/question/3801333
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The molarity is calculated using the following rule:
molarity = number of moles of solvent / volume of solution (in liters)
We have the volume of solution = 250 ml = 0.25 liters and the molarity = 3 m
Substituting in the equation, we get:
3 = number of moles / 0.25
number of moles = 3 x 0.25 = 0.75 moles