Molarity is defined as the ratio of number of moles to the volume of solution in litres.
The mathematical expression is given as:
Here, molarity is equal to 1.43 M and volume is equal to 785 mL.
Convert mL into L
As, 1 mL = 0.001 L
Thus, volume = = 0.785 L
Rearrange the formula of molarity in terms of number of moles:
n =
= 1.12255 mole
Now, Number of moles =
Molar mass of potassium hydroxide = 56.10 g/mol
1.12255 mole =
mass in g =
= 62.97 g
Hence, mass of = 62.97 g
0.24 moles of oxygen must be placed in a 3.00 L container to exert a pressure of 2.00 atm at 25.0°C.
The variables given are Pressure, volume and temperature.
Explanation:
Given:
P = 2 atm
V = 3 litres
T = 25 degrees or 298.15 K by using the formula 25 + 273.17 = K
R = 0.082057 L atm/ mole K
n (number of moles) = ?
The equation used is of Ideal Gas law:
PV = nRT
n =
Putting the values given for oxygen gas in the Ideal gas equation, we get
n =
= 0.24
Thus, from the calculation using Ideal Gas law it is found that 0.24 moles of oxygen must be placed in a container.
Ideal gas law equation is used as it tells the relation between temperature, pressure and volume of the gas.