Answer:
ΔH°rxn = -827.5 kJ
Explanation:
Let's consider the following balanced equation.
2 PbS(s) + 3 O₂(g) → 2 PbO(s) + 2 SO₂(g)
We can calculate the standard enthalpy of reaction (ΔH°rxn) from the standard enthalpies of formation (ΔH°f) using the following expression.
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × ΔH°f(PbO(s)) + 2 mol × ΔH°f(SO₂(g)
)] - [2 mol × ΔH°f(PbS(s)) + 3 mol × ΔH°f(O₂(g)
)]
ΔH°rxn = [2 mol × (-217.32 kJ/mol) + 2 mol × (-296.83)] - [2 mol × (-100.4) + 3 mol × 0 kJ/mol]
ΔH°rxn = -827.5 kJ
The molar mass is 242 g/mol (<span>241.8597 g/mol). There is a very good online service to calculate molar masses:
http://www.webqc.org/mmcalc.php
</span>
The solution that will have the lowest freezing point is 5.0 SODIUM CHLORIDE.
Adding solute to solvents usually result in the depression of the freezing point. The higher the quantity of the solute that is added, the lower the freezing point of the solution.
What is likely to occur if sulfur forms an ionic bond with another element is <u>sulfur will accept electrons</u>
<u><em> explanation</em></u>
- Ionic bond is formed when a metal react with a non metal.
- Metal loses ( donate) electrons to form cation ( a positively charged ion) , while non metal accept (gain) electrons to form anion ( a negatively charged ion ).
- Sulfur is a non metal therefore it accept electrons if it form an ionic bond with a metal. sulfur accept 2 electrons to form S2- ion
Cardiovascular and circulatory
kidneys filter thru blood to take out waste
lungs breathe in oxygen, give blood 2 circulatory to carry! takes co2 out
