A student has placed a mixture of CaO and CaO, 4.88 g of dough into a flask containing 1.46 L of carbon dioxide at 35 ° C and 746 mmHg. After completing the reactions, it found that CO2 pressure had decreased to 353 mmHg.Calcule the percentage composition of the mixture
To calculate the percentage composition of the mixture, we need to determine the quantities of CaO and CaCO3 present in the mixture.
Let's start by calculating the number of moles of carbon dioxide before and after the reaction:
Initial moles of CO2 = (P * V) / (R * T)
Final moles of CO2 = (P * V) / (R * T)
Where:
P = Pressure of CO2 before and after the reaction (in atm)
V = Volume of CO2 (in liters)
R = Ideal gas constant (0.0821 L * atm / mol * K)
T = Temperature in Kelvin (35 + 273 = 308 K)
Initial moles of CO2 = (746 mmHg * 1.46 L) / (0.0821 L * atm / mol * K * 308 K)
Final moles of CO2 = (353 mmHg * 1.46 L) / (0.0821 L * atm / mol * K * 308 K)
Next, we need to calculate the moles of CaO that reacted to form CaCO3 by using the stoichiometry of the reaction:
CaO + CO2 -> CaCO3
From the balanced equation, we can see that 1 mole of CaO reacts with 1 mole of CO2 to produce 1 mole of CaCO3.
Therefore, the moles of CaO reacted = Initial moles of CO2 - Final moles of CO2
Finally, we can calculate the percentage composition of the mixture:
Percentage of CaO = (mass of CaO / total mass of the mixture) * 100
Percentage of CaCO3 = (mass of CaCO3 / total mass of the mixture) * 100
To find the masses of CaO and CaCO3, we need to use their molar masses:
Molar mass of CaO = 56.08 g/mol
Molar mass of CaCO3 = 100.09 g/mol
Once we determine the moles of CaO and CaCO3, we can calculate their respective masses by using their molar masses.
Finally, we use the mass values obtained to calculate the percentage composition of the mixture.
(Note: If there was any additional information regarding the reaction, it would be necessary to consider stoichiometry and any other variables that may affect the reaction or the equilibrium conditions.)