2Ag+(aq) + CO2-_3(aq)-----------Ag2CO3
<u>Answer:</u> The new pressure for oxygen gas is 6 atm.
<u>Explanation:</u>
To calculate the new pressure of the gas, we use the equation given by Boyle's Law.
This law states that the pressure is inversely proportional to the volume of the gas at constant temperature and number of moles.
Mathematically,

or,

where,
are the initial pressure and volume of the gas.
are the final pressure and volume of the gas.
We are given:

Putting values in above equation, we get:

Hence, the new pressure for oxygen gas is 6 atm.
second compound
Let molar mass of x is = X
Let molar mass of y is = Y
Moles of x in second compound = Mass / molar mass = 7 / X
Moles of y in second compound = Mass / molar mass = 4.5 / Y
For second compound
7 / X : 4.5/ Y = 1:1
Therefore
X / Y = 7/4.5
Y / X = 4.5/ 7
The mass of x in first compound = 14g
moles of x in first compound = 14/X
Mass of y in first compound = 3
moles of y in first compound = 3 / Y
14 / X : 3/ Y = 14Y / 3X = 14 X 4.5 / 3 X 7 = 3 :1
Thus molar ratio in first compound = moles of x / Moles of y = 3:2
Formula = x3y