Answer:
Compounds are represented by chemical formulas.
Explanation:
Answer: 1. CaO + H2O => Ca(OH)2
2. P4 + 5O2 => 2P2O5
3. 2 Ca + O2 => 2 CaO
4. 8 Cu + S8 => 8 CuS
5. CaO + H2O => Ca(OH)2
6. S8 + 8 O2 => 8 SO2
7. 3 H2 + N2 => 2 NH3
8. H2 + Cl2 =>2 HCl
9. 16 Ag + S8 => 8 Ag2S
10. Cr + O2 => 2Cr2O3
11. 2Al + 3Br2 => 2AlBr3
12. 2Na + I2 => 2NaI
13. 2H2 + O2 =>2 H2O
14. 4 Al + 3O2 => 2 Al2O3
Explanation:
Because their molecules are more tightly packed. Massdensity = ---------- Volume
So more densely packed molecules means more mass per unit volume. Hence metals are denser than non-metals.
Answer:
0.4694 moles of CrCl₃
Explanation:
The balanced equation is:
Cr₂O₃(s) + 3CCl₄(l) → 2CrCl₃(s) + 3COCl₂(aq)
The stoichiometry of the equation is how much moles of the substances must react to form the products, and it's represented by the coefficients of the balanced equation. So, 1 mol of Cr₂O₃ must react with 3 moles of CCl₄ to form 2 moles of CrCl₃ and 3 moles of COCl₂.
The stoichiometry calculus must be on a moles basis. The compounds of interest are Cr₂O₃ and CrCl₃. The molar masses of the elements are:
MCr = 52 g/mol
MCl = 35.5 g/mol
MO = 16 g/mol
So, the molar mass of the Cr₂O₃ is = 2x52 + 3x35.5 = 210.5 g/mol.
The number of moles is the mass divided by the molar mass, so:
n = 49.4/210.5 = 0.2347 mol of Cr₂O₃.
For the stoichiometry:
1 mol of Cr₂O₃ ------------------- 2 moles of CrCl₃
0.2347 mol of Cr₂O₃----------- x
By a simple direct three rule:
x = 0.4694 moles of CrCl₃
