Suppose that coal of density 1.5 g/cm3 is pure carbon. (It is, in fact, much more compli- cated, but this is a reasonable first approxima- tion.) The combustion of carbon is described by the equation
C(s) + O2(g) −→ CO2(g) ∆H◦ = −394 kJ What is the value of q (heat) when a lump of coal of size 5 cm×4.5 cm×4 cm is burned?
Answer in units of kJ
I want you to show me how to work out,, the calculation,, please ❤️
To find the value of q (heat) when a lump of coal of size 5 cm × 4.5 cm × 4 cm is burned, you can follow these steps:
Step 1: Calculate the volume of the lump of coal.
Volume = Length × Width × Height
Volume = 5 cm × 4.5 cm × 4 cm
Step 2: Convert the volume from cubic centimeters (cm3) to liters (L).
1 L = 1000 cm3
Volume (in L) = Volume (in cm3) / 1000
Step 3: Calculate the mass of the lump of coal.
Density = Mass / Volume
Mass = Density × Volume
Step 4: Convert the density from grams per cubic centimeter (g/cm3) to kilograms per liter (kg/L).
1 kg/L = 1000 g/cm3
Density (in kg/L) = Density (in g/cm3) / 1000
Step 5: Calculate the heat released during combustion.
Heat = q = Mass × ∆H◦
Now let's calculate the values:
Step 1: Volume = 5 cm × 4.5 cm × 4 cm = 90 cm3
Step 2: Volume (in L) = 90 cm3 / 1000 = 0.09 L
Step 3: Mass = Density × Volume = 1.5 g/cm3 × 90 cm3 = 135 g
Step 4: Density (in kg/L) = 1.5 g/cm3 / 1000 = 0.0015 kg/L
Step 5: Heat = q = Mass × ∆H◦ = 135 g × -394 kJ = -53230 kJ (Remember the negative sign in front of ∆H◦ indicates that it is an exothermic reaction)
Therefore, the value of q (heat) when the lump of coal is burned is -53230 kJ.
To find the value of q (heat) when a lump of coal is burned, we need to calculate the energy released during the combustion of the coal. We can do this by first finding the mass of the coal using its density and dimensions, and then using the heat of combustion equation.
1. Find the volume of the lump of coal:
Volume = length × width × height
Volume = 5 cm × 4.5 cm × 4 cm
2. Convert the volume to liters (since the density is given in g/cm3):
Volume (in liters) = Volume (in cm3) / 1000
3. Find the mass of the coal:
Mass = Volume × Density
Mass = Volume (in liters) × Density (in g/cm3)
4. Convert the mass to grams:
Mass (in grams) = Mass (in kg) × 1000
5. Calculate the energy released during combustion:
q = Mass × ∆H◦
where ∆H◦ = -394 kJ (given in the question)
Now we can follow these steps to find the value of q:
Step 1: Calculate the volume
Volume = 5 cm × 4.5 cm × 4 cm
Step 2: Convert the volume to liters
Volume (in liters) = Volume (in cm3) / 1000
Step 3: Find the mass of the coal
Mass = Volume × Density
Note: Density is given as 1.5 g/cm3
Step 4: Convert the mass to grams
Mass (in grams) = Mass (in kg) × 1000
Step 5: Calculate the energy released during combustion
q = Mass × ∆H◦
∆H◦ = -394 kJ
By following these steps, you can calculate the value of q (heat) in units of kJ when a lump of coal of size 5 cm × 4.5 cm × 4 cm is burned.