For which of the following reactions is ΔH∘rxnΔHrxn∘ equal to ΔH∘fΔHf∘ of the product(s)? You do not need to look up any values to answer this question. Check all that apply. View Available Hint(s) Check all that apply. 2Na(s)+Cl2(g)→2NaCl(s)2Na(s)+Cl2(g) →2NaCl(s) Na(s)+12Cl2(l)→NaCl(s)Na(s)+12Cl2(l )→NaCl(s) CaCO3(g)→CaO+CO2(g)CaCO3(g)→CaO+CO2 (g) C(s)+O2(g)→CO2(g)C(s)+O2(g)→CO2(g) CO(g)+12O2(g)→CO2(g)CO(g)+12O2(g)→C O2(g) Na(s)+12Cl2(g)→NaCl(s)Na(s)+12Cl2(g )→NaCl(s) Submit Part B

- 2Na(s)+Cl2(g)→2NaCl(s)

- Na(s)+1/2Cl2(l)→NaCl(s)

- C(s)+O2(g)→CO2(g)

Explanation:

Hello,

In this case, we shall remember that formation reactions are those involving the direct reaction of the elements forming the required compound. In such a way, for the given reactions:

2Na(s)+Cl2(g)→2NaCl(s)

Na(s)+1/2Cl2(l)→NaCl(s)

CaCO3(g)→CaO+CO2(g)

C(s)+O2(g)→CO2(g)

CO(g)+1/2O2(g)→CO2(g)

Just:

2Na(s)+Cl2(g)→2NaCl(s)

Na(s)+1/2Cl2(l)→NaCl(s)

C(s)+O2(g)→CO2(g)

Involve the elements composing the final products at the reactants. For that reason, the enthalpy of reaction (ΔH°rxn) result equal to the enthalpy of formation (ΔH°f) of the given product.

Regards.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.