Ethyl alcohol (CH3CH2OH) has a heat of fusion of 5.01 kj/mol. How much heat in kj is required to melt 137g of ethyl alcohol.
To calculate the heat required to melt a substance, you need to use the formula:
Heat (q) = mass (m) x heat of fusion (ΔHf)
First, convert the given mass of ethyl alcohol from grams to moles. To do this, you need to know the molar mass of ethyl alcohol.
The molar mass of ethyl alcohol (CH3CH2OH) can be calculated by summing up the atomic masses of its constituent elements, which are:
C (carbon) = 12.01 g/mol
H (hydrogen) = 1.01 g/mol
O (oxygen) = 16.00 g/mol
Molar mass of ethyl alcohol (CH3CH2OH) = (2 x C) + (6 x H) + O
= (2 x 12.01) + (6 x 1.01) + 16.00
≈ 46.07 g/mol
Next, calculate the number of moles of ethyl alcohol in 137 grams:
Number of moles (n) = mass (m) / molar mass (M)
= 137 g / 46.07 g/mol
Now that you have the number of moles, use the provided heat of fusion (ΔHf) to calculate the heat required:
Heat (q) = number of moles (n) x heat of fusion (ΔHf)
Substitute the values into the formula:
q = (137 g / 46.07 g/mol) x 5.01 kJ/mol
Calculating this will give you the amount of heat required to melt 137 g of ethyl alcohol in kilojoules (kJ).