Answer:
14.04 L.
Explanation:
- The balanced reaction to form Al₂O₃ is:
<em>4Al + 3O₂ → 2Al₂O₃,</em>
4.0 moles of Al react with 3.0 moles O₂ to produce 2.0 moles Al₂O₃.
- Firstly, we need to calculate the no. of moles in (46.54 grams) of Al₂O₃:
<em>n = mass/molar mass </em>= (46.54 g) / (101.96 g/mol) = <em>0.4565 mol.</em>
<em></em>
<u><em>Using cross multiplication:</em></u>
3.0 moles of O₂ produce → 2.0 mole Al₂O₃, from the stichiometry.
??? moles of O₂ produce → 0.4565 mole Al₂O₃.
<em>∴ The no. of moles of O₂ needed to produce 0.4565 mol (46.54 grams) of Al₂O₃</em> = (3.0 mol)(0.4565 mol)/(2.0 mol) = <em>0.6847 mol.</em>
- To calculate the volume of O₂ needed to produce 0.4565 mol (46.54 grams) of Al₂O₃, we can use the general law of ideal gas: <em>PV = nRT.</em>
where, P is the pressure of the gas in atm (P = 1.2 atm).
V is the volume of the gas in L (V = ??? L).
n is the no. of moles of the gas in mol (n = 0.6847 mol).
R is the general gas constant (R = 0.082 L/atm/mol.K),
T is the temperature of the gas in K (T = 300.0 K).
<em>∴ V = nRT/P</em> = (0.6847 mol)(0.082 L/atm/mol.K)(300.0 K)/(1.2 atm) =<em> 14.04 L.</em>
Answer:
3–ethyl–4–methylhexane.
Explanation:
To name the above compound, do the following:
1. Determine the functional group of the compound.
2. Locate the longest continuous carbon chain. This gives the parent name of the compound.
3. Identify the substituent group attached to the compound.
4. Give the substituent the lowest possible count.
5. Combine the above to name the compound.
Now, we shall name the compound given in the question above as follow:
1. The compound contains only single bond. Therefore, the compound belong to the alkane family.
2. The longest continuous carbon chain is 6 i.e hexane.
3. The substituent group attached are:
i. Methyl, CH3.
ii. Ethyl, CH2CH3.
4. we shall name the substituents alphabetically i.e ethly will come before methyl. Therefore,
Ethyl is located at carbon 3.
Methy is located at carbon 4.
5. Therefore, the name of the compound is:
3–ethyl–4–methylhexane.
Answer:
It is the energy the ions absorb when they form a crystalline compound.
Explanation:
Lattice energy is the energy released upon the formation of a crystal lattice structure.
Answer:
i. n = 5
ii. ΔE = 7.61 × 
KJ/mole
Explanation:
1. ΔE = (1/λ) = -2.178 × 
(
- 
)
(1/434 × 
) = -2.178 × (
)
⇒ 434 × = (1/-2.178 × )
But, 
= 2
434 × = (1/2.178 × )
434 × × 2.178 × = 
⇒ 
= 5
Therefore, the initial energy level where transition occurred is from 5.
2. ΔE = hf
= (hc) ÷ λ
= (6.626 × 10−34 × 3.0 × 
) ÷ (434 × )
= (1.9878 × 
) ÷ (434 × )
= 4.58 × 
J
= 4.58 × 
KJ
But 1 mole = 6.02×
, then;
energy in KJ/mole = (4.58 × KJ) ÷ (6.02×)
= 7.61 × KJ/mole
