To get the value of ΔG we need to get first the value of ΔG°:
when ΔG° = - R*T*㏑K
when R is constant in KJ = 0.00831 KJ
T is the temperature in Kelvin = 25+273 = 298 K
and K is the equilibrium constant = 4.5 x 10^-4
so by substitution:
∴ ΔG° = - 0.00831 * 298 K * ㏑4.5 x 10^-4
= -19 KJ
then, we can now get the value of ΔG when:
ΔG = ΔG° - RT*㏑[HNO2]/[H+][NO2]
when ΔG° = -19 KJ
and R is constant in KJ = 0.00831
and T is the temperature in Kelvin = 298 K
and [HNO2] = 0.21 m & [H+] = 5.9 x 10^-2 & [NO2-] = 6.3 x 10^-4 m
so, by substitution:
ΔG = -19 KJ - 0.00831 * 298K* ㏑(0.21/5.9x10^-2*6.3 x10^-4 )
= -40
Answer:
17.3 g Cr
Explanation:
To find the mass of chromium, you need to (1) convert moles Si to moles Cr (using the mole-to-mole ratio from equation coefficients) and then (2) convert moles Cr to grams Cr (using the atomic mass). It is important to arrange the conversions in a way that allows for the cancellation of units. The final answer should have 3 sig figs to match the sig figs of the given value (0.250).
3 Si + 2 Cr₂O₃ ---> 4 Cr + 3 SiO₂
^ ^
Atomic Mass (Cr): 51.996 g/mol
0.250 moles Si 4 moles Cr 51.996 g
------------------------- x -------------------- x ------------------- = 17.3 g Cr
3 moles Si 1 mole
Cu(OH)2 is the precipitate that forms
<span>SO3
for the formal charges, we have:
for the single-bonded oxygens F.C. = 6 - [1/2(2) + 6] = -1
for the double-bonded oxygen F.C. = 6 - [1/2(4) + 4] = 0
for the sulfur F.C. = 6 - [1/2(8) + 0] = 2
Again, the formal charges add to zero. The oxidation numbers of O and S are -2 and +6, respectively. Note the three resonance forms!</span>
