Consider the reaction, C2H4 (g) + H2 (g)- C2H6 (g) where -137kJ of heat is released.
How many kilojoules are released when 55.3g of C2H4 reacts?
270. kJ are released.
137 kJ heat released for 28 g C2H4. You have 55.3g; therefore, heat released will be 137 kJ x (55.3/28) = ??
Another way to look at it.
This is 137 kJ heat released per mol C2H4.How many moles do you have?
That is 55.3/28 = 1.975 moles
Then 1.37 kJ/mol x 1.975 mol = ??
Well, let's do some chemistry math here. We start by finding the molar mass of C2H4, which is 28.05 g/mol. So, if we have 55.3 g of C2H4, we can divide that by the molar mass to find the number of moles: 55.3 g / 28.05 g/mol = 1.97 mol. Now, if we look at the balanced chemical equation, we see that the reaction releases -137 kJ of heat per 1 mol of C2H4. So, to find the total amount of heat released, we multiply this value by the number of moles we have: -137 kJ/mol * 1.97 mol = -269.89 kJ. Therefore, approximately -269.89 kJ of heat would be released when 55.3 g of C2H4 reacts. But hey, remember that the negative sign just means the reaction is exothermic. It's not like the kilojoules are running away screaming or anything.
To determine the number of kilojoules released when 55.3g of C2H4 (ethylene) reacts, we need to use the concept of molar ratios and the molar enthalpy of the reaction.
First, we need to find the number of moles of C2H4 (ethylene) by dividing the given mass by its molar mass. The molar mass of C2H4 can be calculated as follows:
C: 12.01 g/mol (atomic mass of carbon)
H: 1.01 g/mol (atomic mass of hydrogen)
Molar mass of C2H4 = (2 × 12.01 g/mol) + (4 × 1.01 g/mol) = 28.05 g/mol
Now, we can calculate the number of moles of C2H4:
moles of C2H4 = mass of C2H4 / molar mass of C2H4
= 55.3 g / 28.05 g/mol
≈ 1.971 mol
Next, we need to determine the heat released for 1 mole of C2H4. The balanced equation tells us that the reaction releases 137 kJ of heat for 1 mole of C2H4 reacted.
Given that the reaction releases 137 kJ per 1 mol of C2H4, we can calculate the heat released for 1.971 mol (the number of moles we calculated earlier):
Heat released = 137 kJ/mol × 1.971 mol
≈ 269.367 kJ
Therefore, approximately 269.367 kJ of heat is released when 55.3g of C2H4 reacts.