Answer:
0.46 V
Explanation:
The emf for the cell is given by:
Eº cell = Eº oxidation + Eº reduction
From the given balanced chemical equation, we can deduce that Fe²⁺ has been oxidized to Fe³⁺, and O reduced from 0 to negative 2, according to the half cell reactions:
4Fe²⁺ ⇒ Fe³⁺ + 4e⁻ oxidation
O₂ + 4H⁺ + 4 e⁻ ⇒ 2 H₂O reduction
From reference tables for the standard reduction potential, we get
Eº red Fe³⁺ / Fe²⁺ Eºred = 0.77 V
Eº red O₂ / H₂O Eºred = 1.23 V
Now all we need to do is change the sign of Eº reduction for the species being oxidized ( Fe²⁺ ) and add it to Eº reduction O₂:
Eº cell = Eº oxidation + Eº reduction = - (0.77 V ) + 1.23 V = 0.46 V
Water moved through the water cycle by changing its state. Think, for example, of water evaporating (liquid to gas), snow sublimating (solid to gas) or melting (solid to liquid), rain (gas to liquid), sleet (liquid to solid), or snow (gas to solid).
The answer would thus be A.
The net ionic equation is shorter to use and already leaves out the electrons that transferred from the reducing agent to the oxidizing agent. Also, in some occasions the aqueous ions H+ and (or) OH- ions that help balance the net ionic charge are no longer shown in the net ionic equation.
Answer:
Cultural Pest Control.
Explanation:
The cultural pest control is one of the oldest methos of pest control. This form of pest control is less practiced these days since curative form of pest control methods have been invented. The cultural pest control method is a preventive method of managing pest population. This pest control method takes long days of planning and execution.
<u>In this form of pest control method, the farmer had to change the timings of his farming operations in his field. This method requires careful timing in seeding and planting. This method of pest controlling requires knowledge and skills of fields</u>.
Thus the correct answer is the third option.
