Answer:
Standard enthalpy of formation of Carbon disulfide CS2 = 87.3 KJ/mol
Explanation:
forming CS2 means that it should in the product side
C(graphite) + O2 → CO2 ΔH = -393.5
2S(rhombic) + 2O2 → 2SO2 ΔH = -296.4 x 2
CO2 + 2SO2 → CS2 + 3O2 ΔH = -1073.6 x -1
the second reaction is multiplied by 2 so that the SO2 and O2 can cancel out.
the third reaction is reversed (multiplied by -1) so that CS2 will be on the product side.
after adding the reaction and cancelling out similarities, the final reaction is: C(graphite) + 2S(rhombic) → CS2
Add ΔH to find the enthalpy of formation of CS2
ΔHf = (-393.5) + (-296.4 x 2) + (-1073.6 x -1) = 87.3 KJ/mol
be aware of signs
There are two things that could be done. The first is to increase the mass of the objects. The second is to decrease the distance between the center of masses of the objects.
The correct answer is: [C]: "polar" .
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" Water " ; which is: " H₂O " ;
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is a:
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— polar; → {eliminate: "Choice [A]: "non-polar"} ;
→ {and consider: "Choice: [C]: "polar" } ;
— covalent; → {not "ionic"; eliminate: "Choice: [B]: "ionic"} ;
— uncharged; → {neutral compound; not "charged" —but "balanced"} ;
→ {Note: " H ⁺ , O ²⁻ ; → " H₂O " } ;
→ The "charges" balance/ cancel out.
→ {eliminate: "Choice: [D]: "charged" .}.
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— compound.
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The correct answer is: [C]: "polar" .
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Answer:
1. Magnesium(Mg)
2.Calcium(Ca)
3.Nitrogen(N)
4.Carbon(C)
5.Mercury(Hg)
6.Gallium(Ga)
Explanation:
1.Neutral means same no. of protons and electrons which is atomic number.So element with Atomic number 12 is Magnesium.
2. No. of protons = Atomic number.So element with Atomic number 20 is Calcium.
3.Neutral means same no. of protons and electrons which is atomic number.So element with Atomic number 7 is Nitrogen.
4.C-14 isotope has two extra neutrons making it 6+2= 8 neutrons.
5.Mercury(Hg) is the name of element.
6.Gallium(Ga) and Aluminium together belongs to Aluminium family.
