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
Answer is: B. C(s) + 2S(s) + 89.4 kJ → CS2(l).
Missing question:
A. C(s) + 2S(s) → CS2(l) + 89.4 kJ.
B. C(s) + 2S(s) + 89.4 kJ → CS2(l).
C. C(s) + 2S(s) + 89.4 kJ → CS2(l) + 89.4 kJ.
D. C(s) + 2S(s) → CS2(l).
Because enthalpy of
the system is greater that zero, this is endothermic reaction (<span>chemical reaction that
absorbs more energy than it releases)</span>, heat is included as a reactant.
You can see wich group by the last out shell. Group 1 has 1 electron in the outershell
1) Answer is: 5.
Chemical dissociation of aluminium sulfide in water:
Al₂S₃(aq) → 2Al³⁺(aq) + 3S²⁻(aq).
There are five ions, two aluminium cations and three sulfide anions.
2) Answer is: 4.
Chemical dissociation of aluminium fluoride in water:
AlF₃(aq) → Al³⁺(aq) + 3F⁻(aq).
There are four ions, one aluminium cation and three fluoride anions.
Aluminium has oxidation +3, because it lost three electrons, to gain electron configuration as noble gas neon.
Answer:
You would use an electrolytic cell.
