Answer:
Because the molecules have not been in water so they are not moving around each other
Explanation:
When a water vapor condenses, heat is being released from the process. This heat is called latent heat of vaporization since the phase change happens without any change in the temperature. This value is constant per mole of a substance as a function of pressure and temperature. For this problem, we are given the heat of vaporization at a certain T and P. We use this value to calculate the total heat released from the process. We calculate as follows:
Total heat released: 32.4 g ( 1 mol / 18.02 g ) (40.67 kJ / mol) = 73.12 kJ
Therefore, 73.12 kJ of heat is released from the condensation of 32.4 g of water vapor.
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.
Answer:
pH = 7.8
Explanation:
The Henderson-Hasselbalch equation may be used to solve the problem:
pH = pKa + log([A⁻] / [HA])
The solution of concentration 0.001 M is a formal concentration, which means that it is the sum of the concentrations of the different forms of the acid. In order to find the concentration of the deprotonated form, the following equation is used:
[HA] + [A⁻] = 0.001 M
[A⁻] = 0.001 M - 0.0002 M = 0.0008 M
The values can then be substituted into the Henderson-Hasselbalch equation:
pH = 7.2 + log(0.0008M/0.0002M) = 7.8
