Answer:
a. x = + 2
b. x = + 3
c. x = + 2
d. x = + 3
Explanation:
The oxidation number is a formal charge assigned to an atom present in a molecule or formula unit or ion based on some arbitrary rules.
a.
<u>Hg</u>O
The oxidation number of Hg in HgO is:
x + (-2) = 0
x = +2
b.
<u>Al₄</u>C₃
The oxidation number of Al in Al<u>₄</u>C₃ is:
4x +(3 × -4) = 0
4x - 12 = 0
4x = +12
x = 12/4
x = +3
c. CrF₂
x + ( 2 × - 1) = 0
x - 2 = 0
x = + 2
d. Fe₂S₃
2x + ( 3 × - 2) = 0
2x + (-6) = 0
2x = 6
x = 6/2
x = +3
ΔG > 0
is always true for the freezing of water.
Explanation:
- The freezing of water is only spontaneous when the temperature is fairly small. Over 273 K, the higher value of TΔS causes the sign of ΔG to be positive, and there is no freezing point.
- The entropy decreases as water freezes. This does not infringe the Thermodynamics second law. The second law doesn't suggest entropy will never diminish anywhere.
- Entropy will decline elsewhere, provided it increases by at least as much elsewhere.
Answer:
mass (g) needed = 710.2 grams Na₂SO₄(s)
Explanation:
Needed is 2.5 Liters of 2.0M Na₂SO₄; formula wt Na₂SO₄ = 142.04g/mol.
mass (grams) of Na₂SO₄(s) = Molarity needed x Volume needed in Liters x Formula Wt of solute
mass (grams) of Na₂SO₄(s) = (2.5L)(2.0M)(142.04g/mol) = 710.2 grams Na₂SO₄(s)
Mixing: Transfer 710.4 grams Na₂SO₄ into mixing vessel and add water-solvent up to but not to exceed 2.5 Liters total volume. Mix until dissolved.
Gives 2.5 Liters of 2.0M Na₂SO₄(aq) solution.
<em>The formula of calcium carbonate is CaCO3
</em>
<em>The formula of nitric acid is HNO3.
</em>
<em>When put together:</em>
<em>CaCO3 + HNO3 </em><em>= </em><em>Ca(NO3)2 + CO2 + H2O
</em>
<em>
The balanced equation:</em>
<em>
CaCO3 + 2HNO3</em><em> = </em><em>Ca(NO3)2 + CO2 + H2O
</em>
<em>
</em>
<em></em>
With a pH of 2, it's very acidic and far from a neutral pH and basic. I would say chemical as my answer.
