In the reaction C(s) + 2S(s) �¨ CS2(l), the change of enthalpy (ƒ¢H) is 89.3 kJ. Calculate the amount of heat absorbed when 6.33 g of carbon disulfide is formed.
What does the equation tell you? That 89.3 kJ are absorbed when 1 mol (76.1g CS2) are formed. You have 6.33 g; therefore,
89.3 kJ x (6.33/76.1) = ? kJ
To calculate the amount of heat absorbed when 6.33 g of carbon disulfide (CS2) is formed, we need to use the equation:
q = m * ĢH
Where:
q is the amount of heat absorbed (in joules or calories)
m is the mass of the substance (in grams)
ĢH is the change in enthalpy (in joules or calories) of the reaction
First, we need to convert the mass of CS2 from grams to moles. To do this, we use the molar mass of CS2, which can be calculated using the atomic masses of carbon (C) and sulfur (S).
The molar mass of C = 12.01 g/mol
The molar mass of S = 32.07 g/mol
Therefore, the molar mass of CS2 = (12.01 * 1) + (32.07 * 2) = 76.15 g/mol
Next, we can calculate the number of moles of CS2 present in 6.33 g of CS2 using the equation:
moles = mass / molar mass
moles = 6.33 g / 76.15 g/mol
Now that we have the number of moles of CS2, we can calculate the amount of heat absorbed (q) using the equation mentioned earlier:
q = moles * ĢH
Substituting the values we have, we get:
q = moles * ĢH
Finally, we can plug in the values to find the amount of heat absorbed.
To calculate the amount of heat absorbed when 6.33 g of carbon disulfide (CS2) is formed, we need to use the given change in enthalpy (ΔH) value and the molar mass of CS2.
Step 1: Calculate the molar mass of CS2
The molar mass of carbon (C) is 12.01 g/mol, and the molar mass of sulfur (S) is 32.07 g/mol. CS2 has one carbon atom and two sulfur atoms.
Molar mass of CS2 = (12.01 g/mol) + 2(32.07 g/mol) = 76.15 g/mol
Step 2: Convert grams of CS2 to moles
We are given that the mass of CS2 is 6.33 g.
Number of moles = mass (g) / molar mass (g/mol)
Number of moles = 6.33 g / 76.15 g/mol ≈ 0.083 moles
Step 3: Calculate the amount of heat absorbed
The change in enthalpy (ΔH) is given as 89.3 kJ.
The amount of heat absorbed can be calculated using the equation:
Heat absorbed = moles * ΔH
Heat absorbed = 0.083 moles * 89.3 kJ/mol
Heat absorbed = 7.39 kJ
Therefore, the amount of heat absorbed when 6.33 g of carbon disulfide is formed is approximately 7.39 kJ.