Answer:
0.37 %
Explanation:
Given that:
Calculated density of aluminum = 2.69 g/cm³
Accepted density of aluminum = 2.70 g/cm³

Thus, applying values as:

<u>Percent error = 0.37 %</u>
Answer:
8.5 moles of Al₂O₃ will formed
Explanation:
Given data:
Number of moles of Al = 17 mol
Number of moles of Al₂O₃ formed = ?
Solution:
Chemical equation:
4Al + 3O₂ → 2Al₂O₃
Now we will compare the moles of Al₂O₃ with Al.
Al : Al₂O₃
4 : 2
17 : 2/4×17 = 8.5 mol
8.5 moles of Al₂O₃ will formed.
Answer:
Zero
Explanation:
Recall that;
E = q + w
Where;
q = heat, w = work done
When heat is absorbed by the system q is positive
When heat is evolved by the system q is negative
When the system does work, w is negative
When work is done on the system w is positive
Step 1
ΔE1= 60 KJ + 40 KJ = 100KJ
Step 2
ΔE2= (-30 KJ) + (-70 KJ) = (-100) KJ
ΔE1 + ΔE2= 100KJ + (-100) KJ = 0KJ
Boiling point
i hope this helps.