The heat of combustion for methanol is 727 kj/mol
<em><u>calculation</u></em>
calculate the moles of methanol (CH3OH)
moles = mass/molar mass
molar mass of methanol = 12 +( 1 x3) +16 + 1= 32 g /mol
moles is therefore= 64.0 g / 32 g/mol = 2 moles
Heat of combustion is therefore = 1454 Kj / 2 moles = 727 Kj/mol
to the proper number of significant figures) to the following? (12.67+19.2)(3.99)/(1.36+ 11.366).
Percentage error is the relative error your measured value is from the true or accepted value. The formula for percentage error is written below:
Percentage error = |True Value - Measured Value|/True Value * 100
Percentage error = |0.75 g/mL - 0.78 g/mL|/0.75 g/mL * 100
Percentage error = 4%
Explanation:
Formation of crystals starts with formation of ions. After the formation of ions the bond formation takes place between the ions.
Bond making between the ions give rise to formation of cubic unit cell by placing them in such a fashion that it forms a shape of a cube.
These cube are then arranged in a repeated pattern which ultimately leads to the formation of crystals.
Hence, the order of steps:
Step 1 : Formation of ions
Step 2: Formation of ionic bonds
Step 3: Formation of cubes
Step 4: Formation of crystals
The reaction is:
4 PCl3 (g) ---> P4(s) + 6 Cl2(g).
Now, you need to convert the mass of PCl3 into number of moles, for which you use the molar mass of PCl3 in this way:
number of moles = number of grams / molar mass =>
number of moles of PCl3 = 612 g / 137.32 g/mol = 4.4567 moles of PCl3.
Now use the proportion with the ΔH rxn given.
4 mol PCl3 / 1207 kJ = 4.4567 mol / x => x = 4.4567 mol * 1207 kJ / 4 mol = 1,344.8 kJ = 1.34 * 10^3 kJ.
Answer: 1.34 * 10 ^3 kJ (option d)
