Answer:
Empirical formula is Cr₂O₃.
Explanation:
Given data:
Percentage of Cr = 68.4%
Percentage of O = 31.6%
Empirical formula = ?
Solution:
Number of gram atoms of Cr = 68.4 / 52 = 1.3
2
Number of gram atoms of O = 31.6 / 16 = 1.98
Atomic ratio:
Cr : O
1.32/1.32 : 1.98/1.32
1 : 1.5
Cr : O = 1 : 1.5
Cr : O = 2(1 : 1.5)
Empirical formula is Cr₂O₃.
Answer:
Oxygen with 0.36 moles left over
Explanation:
Answer:
The solution's new volume is 1.68 L
Explanation:
Dilution is the procedure to prepare a less concentrated solution from a more concentrated one, and simply consists of adding more solvent. So, in a dilution the amount of solute does not vary, but the volume of the solvent varies.
In summary, a dilution is a lower concentration solution than the original.
The way to do the calculations in a dilution is through the expression:
Ci*Vi=Cf*Vf
where C and V are concentration and volume, respectively; and the i and f subscripts indicate initial and final respectively.
In this case, being:
- Ci= 7 M
- Vi= 0.60 L
- Cf= 2.5 M
- Vf=?
Replacing:
7 M*0.60 L= 2.5 M* Vf
Solving:

Vf= 1.68 L
<u><em>The solution's new volume is 1.68 L</em></u>