Answer:
ΔH°f P4O10(s) = - 3115.795 KJ/mol
Explanation:
- P4O10(s) + 6H2O(l) ↔ 4H3PO4(aq)
- ΔH°rxn = ∑νiΔH°fi
∴ ΔH°rxn = - 327.2 KJ
∴ ΔH°f H2O(l) = - 285.84 KJ/mol
∴ ΔH°F H3PO4(aq) = - 1289.5088 KJ/mol
⇒ ΔH°rxn = (4)(- 1289.5088) - (6)(- 285.84) - ΔH°f P4O10(s) = - 327.2 KJ
⇒ ΔH°f P4O10(s) = - 5158.035 + 1715.04 + 327.2
⇒ ΔH°f P4O10(s) = - 3115.795 KJ/mol
<span> Find the molar mass of calcium acetate...158.165g.
So start with 255g Calcium acetate x 1 mole Calcium Acetate/158.165 g Calcium Acetate x 6 mol Hydrogen/1 mole Calcium Acetate x 6.022e23 atoms/mole.
So...(255 x 1 x 6 x 6.022e23)/(158.165 x 1 x 1) = 5.825e24 hydrogen atoms</span>
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Answer:
The pressure in the gas is 656mmHg
Explanation:
In calculating the pressure of the gas;
step 1: convert the height of the mercury arm to mmHg
9.60cm = 96.0 mmHg
step 2: convert 752 torr to mmHg
I torr is 1 mmHg
752 torr = 752mmHg
Step 3: since the level of mercury in the container is higher than the level of mercury exposed to the atmosphere, we substrate the values to obtain our pressure.
So, 752mmHg - 96mmHg = 656mmHg
The pressure in the gas container is therefore 656mmHg.
N. B : if the mercury arm is in lower position, you add.
Before proceeding, we should write the reaction equation to better understand what is happening:
2AgNO₃ + Na₂S → Ag₂S + 2NaNO₃
Now, we may apply the law of conservation of mass, due to which the total mass before a chemical reaction is equivalent to the total mass after a chemical reaction. Therefore:
Mass of silver nitrate + mass of sodium sulfide = mass of silver sulfide + mass of sodium nitrate
Mass of silver nitrate + 156.2 = 595.8 + 340
Mass of silver nitrate = 779.6 grams
Answer:
3 moles of O2 needed
Explanation:
2 moles of Mg to one mole O2
so 3 moles of O2 needed
