Answer:
ΔH°rxn = -47 kJ
Explanation:
Using Hess´s law for the reaction:
3 Fe2O3(s) + CO(g) → 2 Fe3O4(s) + CO2(g) ,
the ΔH°rxn will be given by the expression:
ΔH°rxn kJ = 2ΔHºf(Fe3O4) + ΔHºf(CO2) - ( 3ΔHºf(Fe2O3) + ΔHºf(CO) )
= 2(-1118) + (-394) - ( 3( -824 ) + ( -111 ) )
= - 47 kJ
824 g NH3 (1 mol/17 g NH3) (4 mol NO/4mol NH3)
48.47 moles NO
B. 1, 1, 1, 2
Explanation:
You only need to balance the NaNO3 on the right. Since there is 2 NO3 on the left, you need to put a 2 in front of the NaNO3 on the right. Everything else is already balanced so the only coefficient needed is 2 in front of the NaNO3.
c. table salt is a metalloid with properties of both reactants
Answer:
B: electronegativity
Explanation:
Electronegativity is the measure of how strongly atoms attract bonding electrons to themselves.
A is incorrect because Atomic radius though decreases as you go from lithium to fluorine of the periodic table. Atomic radius increases when you go from either top to bottom of the periodic table, or if you go from right to left. So answer A is inaccurate.
C is incorrect because in period 2, all the elements have two electron subshells. For example, Al has 13 electrons. So it has two electron subshells. This is since the first subshell has only two valence electrons and while the second subshell in Al has 11 valence electrons. Therefore, it is inaccurate to say this answer.
D is incorrect because in the first shell, you can only have a max of two electrons. The first shell neither decreases or increases. Therefore, D is inaccurate too.
B is correct because as you go from the periodic table from left to right, the electronegativity and ionization energy increases. This is since the more valence electrons an element has, the more electronegative is. Fluorine for example is desperately trying to get one more electron to have a total of 8 electrons. It wants to have a full shell. Therefore, B is the most relevant answer.
