<span>Zn(OH)4= ; -2 = -4 + ?, Zn = +2 , the -4 is the charge on the 4 OH- ions.
NO3- + 6 H2O + 8 e- -------> NH3 + 9 OH-
( Zn + 4 OH- ----> Zh(OH)4= + 2e-) x 4
7 OH- + NO3- + 4 Zn + 6 H2O -------> NH3 + 4 Zn(OH)4</span>
Answer:
- 1273.02 kJ.
Explanation:
This problem can be solved using Hess's Law.
Hess's Law states that <em>regardless of the multiple stages or steps of a reaction, the total enthalpy change for the reaction is the sum of all changes. This law is a manifestation that enthalpy is a state function.</em>
- We should modify the given 3 equations to obtain the proposed reaction:
<em>6C(s) + 6H₂(g) + 3O₂(g) → C₆H₁₂O₆(s),</em>
<em></em>
- We should multiply the first equation by (6) and also multiply its ΔH by (6):
6C(s) + 6O₂(g) → 6CO₂(g), ∆H₁ = (6)(–393.51 kJ) = - 2361.06 kJ,
- Also, we should multiply the second equation and its ΔH by (6):
6H₂(g) + 3O₂(g) → 6H₂O(l), ∆H₂ = (6)(–285.83 kJ) = - 1714.98 kJ.
- Finally, we should reverse the first equation and multiply its ΔH by (- 1):
6CO₂(g) + H₂O(l) → C₆H₁₂O₆(s) + 6O₂(g), ∆H₃ = (-1)(–2803.02 kJ) = 2803.02 kJ.
- By summing the three equations, we cam get the proposed reaction:
<em>6C(s) + 6H₂(g) + 3O₂(g) → C₆H₁₂O₆(s),</em>
<em></em>
- And to get the heat of reaction for the production of glucose, we can sum the values of the three ∆H:
<em>∆Hrxn = ∆H₁ + ∆H₂ + ∆H₃ =</em> (- 2361.06 kJ) + (- 1714.98 kJ) + (2803.02 kJ) = <em>- 1273.02 kJ.</em>
Answer:
10.70grams
Explanation:
Density of a substance = mass/volume
At STP of a gas (standard temperature and pressure), the density of oxygen gas is 1.429 g/L
Hence, according to this question, in 7.49 L of oxygen gas, there would be:
Using D = m/V
1.429 = m/7.49
m = 1.429g/L × 7.49L
m = 10.70g
Answer:
A the uneven heating of earths surface
Explanation:
Because earths rotates on its axis, circulating air is deflected torward the right in the northern hemisphere and toward the left Southern Hemisphere. This is called the coriolis effect
