Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
None of the above I believe it is what can form a tornado??
Answer:
Explanation:
Assume we have 100g of this substance. That means we would have 20.24g of Cl and 79.76g of Al. Now we can find how many moles of each we have:
= 2.25 mol of chlorine
= 0.750 mol of Al.
To form a integer ratio, do 2.25/0.75 = 2.99999 ~= 3.
So the ratio is essentially Al : Cl => 1 : 3. To the compound is possibly 
.
However, it says it has a molar mass of 266.64 g/mol, and since AlCl3 has a molar mass of 133.32, it must be 
.
Actually this molecule isn't exactly AlCl3 (which is ionic). Al2Cl6 forms a banana bond where Cl acts as a hapto-2 ligand. But that's a bit advanced. All you need to know is X = Al2Cl6
1) Chemical reaction:
Fe2O3 + 2Al ---> Al2O3 + 2Fe
2) molar ratios
1 mol Fe2O3 : 2Al : 1 mol Al2O3 : 2 mol Fe
3) Convert 15.0 g of iron into moles
atomic mass Fe = 55.8 g/mol
moles = mass in grams / atomic mass = 15.0 g / 55.8 g/mol = 0.269 mol
4) Use proportions to determine the moles of Fe2O3, Al, and Al2O3
a) 1mol Fe2O3 / 2 mol Fe = x / 0.269 mol Fe
x =
=> x = 0.269 mol Fe * 1 mol Fe2O3 / 2 mol Fe = 0.134 mol Fe2O3
b) 2 mol Al / 2 mol Fe = x / 0.269 mol Fe
=> x = 0.269 mol Al
c) 2 mol Fe / 1 mol Al2O3 = 0.269 mol Fe / x
=> x = 0.269 mol Fe * 1 mol Al2O3 / 2 mol Fe
x = 0.134 mol Al2O3
5) Convert moles to grams
a) Fe2O3
molar mass Fe2O3 = 2* 55.8 g/mol + 3*16g/mol = 159.6 g/mol
mass = molar mass * number of moles
mass = 159.6 g/mol * 0.134 mol = 21.4 g
b) Al
atomic mass = 27.0 g/mol
mass = number of moles * atomic mass = 0.269 mol * 27.0 g/mol = 7.26 g
c) Al2O3
molar mass = 2 * 27.0 g/mol + 3*16.0 g/mol = 102.0g/mol
mass Al2O3 = numer of moles * molar mass = 0.134 mol * 102.0 g/mol = 13.7 g
Answers:
21.4 g Fe2O3
7.26 g Al
13.7 g Al2O3
