Calculate the heat released when 1.61 L of Cl2(g) with a density of 1.88 g/L reacts with an excess of sodium metal at 25°C and 1 atm to form sodium chloride.
To calculate the heat released in this reaction, we need to first determine the moles of chlorine gas (Cl2) that reacted.
Step 1: Convert the given volume of chlorine gas to moles.
We can use the ideal gas law to convert the volume of chlorine gas (V) to moles (n) by using the following equation:
PV = nRT
Where:
P = pressure (1 atm)
V = volume of gas (1.61 L)
n = moles of gas (unknown)
R = ideal gas constant (0.0821 L·atm/mol·K)
T = temperature in Kelvin (25°C = 298 K)
Rearranging the equation and plugging in the given values, we get:
n = PV / RT
n = (1 atm * 1.61 L) / (0.0821 L·atm/mol·K * 298 K)
n ≈ 0.0771 mol
Step 2: Use stoichiometry to determine the moles of sodium metal (Na) that reacted.
The balanced chemical equation for this reaction is:
Cl2 + 2Na -> 2NaCl
For every one mole of chlorine gas (Cl2), two moles of sodium metal (Na) react. Therefore, the number of moles of sodium metal is twice the number of moles of chlorine gas.
Number of moles of sodium metal = 2 * 0.0771 mol = 0.1542 mol
Step 3: Calculate the heat released using the stoichiometry of the reaction.
From the balanced equation, we know that the molar ratio between chlorine gas and sodium chloride is 1:2.
This means that for every one mole of chlorine gas reacted, two moles of sodium chloride (NaCl) are produced.
Since the density of chlorine gas is given as 1.88 g/L, we can use this information to find the mass of chlorine gas reacted:
Mass of chlorine gas = Density * Volume
Mass of chlorine gas = 1.88 g/L * 1.61 L
Mass of chlorine gas ≈ 3.0288 g
Now we can calculate the molar mass of chlorine gas:
Molar mass of Cl2 = 2 * atomic mass of Cl
Molar mass of Cl2 = 2 * 35.453 g/mol = 70.906 g/mol
Next, calculate the amount of heat released in the reaction using the molar mass of chlorine gas and enthalpy change (ΔH) per mole of Cl2:
Heat released = ΔH * moles of Cl2
Note: The enthalpy change (ΔH) value for the reaction is not provided in the question, so this value is required to calculate the heat released.
Finally, substitute the values to calculate the heat released.