How many grams of CO2 are needed to neutralize a 5 liters water with a pH of 11 to 7? under the following conditions:
P: 4000 psi, T:230 oF
Note: CO2 is a one of oil reservoir fluid components with mole percent 0f 3.6%.
thanks a million
To determine the amount of CO2 needed to neutralize the water, we need to calculate the moles of CO2 required and then convert it to grams.
Step 1: Calculate the moles of H+ ions in the water.
The water has a pH of 11, which means it is basic. To neutralize it to a pH of 7, we need to add or generate an equal number of H+ ions. From basic chemistry principles, we know that the pH scale is logarithmic, and each integer change in pH represents a 10-fold change in the concentration of H+ ions. Therefore, to neutralize the water from pH 11 to pH 7, we need to add 10^4 times more H+ ions.
Step 2: Calculate the moles of CO2 required.
According to the balanced chemical equation, 1 mole of CO2 reacts with 2 moles of H+ ions. Therefore, the number of moles of CO2 required will be half of the number of moles of H+ ions added in step 1.
Step 3: Convert moles of CO2 to grams.
To convert moles of CO2 to grams, we need to use the molar mass of CO2. The molar mass of CO2 is approximately 44 g/mol.
Given the pressure and temperature conditions, we can use the Ideal Gas Law to calculate the mole percent of CO2 in the oil reservoir fluid:
PV = nRT
Where:
P = pressure in atm (since 4000 psi is not in atm, we need to convert it)
V = volume in liters (5 liters in this case)
n = number of moles of the gas
R = ideal gas constant (0.0821 L.atm/(mol.K))
T = temperature in Kelvin (since 230 °F is not in Kelvin, we need to convert it)
Step 4: Calculate the mole percent of CO2 in the oil reservoir fluid.
Convert pressure to atm:
1 atm = 14.7 psi
4000 psi = 4000/14.7 atm
Convert temperature to Kelvin:
T(K) = (T(°F) - 32) * 5/9 + 273.15
Calculate the number of moles of CO2 using the Ideal Gas Law.
Step 5: Calculate the moles of CO2 required to neutralize the water.
Multiply the mole percent of CO2 in the oil reservoir fluid by the number of moles of CO2 calculated in step 2.
Step 6: Convert moles of CO2 to grams.
Multiply the moles of CO2 by the molar mass of CO2 (44 g/mol) to get the mass in grams.
Keep in mind that this calculation assumes ideal conditions and does not account for any other chemical reactions that may occur when CO2 is introduced to water. It's always advisable to consult with a professional in the field for accurate and precise calculations.