Answer:
The amount of energy liberated will be 49.38 J.
Explanation:
The amount of energy liberated (gibbs free energy) can be calculated using the following equation:
ΔG° = -nFε
n: amount of moles of electrons transfered
F: Faraday's constant
ε: cell potential
20.0 g of Zn is equal to 0.30 mol.
Two electrons are transfered during the reaction.
Therefore, n = 2x0.30 ∴ n = 0.60
ΔG° = - 0.60 x 96.485 x 0.853
ΔG° = 49.38 J
Some of the NH₄+ will combine with the OH- and shift the equilibrium backwards and from NH₄OH to balance the change produced by addition of NH₄+ ions.
Answer:
C. To determine how efficient reactions are.
D. To determine how much reactant they need.
Explanation:
When you are doing a reaction, you are hoping for a percent yield to close of 100%. You make the reaction and determine how many product you obtain. If you know the percent yield of a reaction you can calculate the amount of reactant you need to obtain a determined amount of product.
Having this in mind:
A. To balance the reaction equation. false. To calculate percent yield you need to balance the reaction before. You don't use percent yield to balance the reaction
B. To determine how much product they will need. false. You determine how much product you obtain after the reaction. How much product you need is independent of percent yield
C. To determine how efficient reactions are. true. A way to determine efficience of a reaction is with percent yield. An efficient reaction has a high percent yield.
D. To determine how much reactant they need. true. If you know percent yield of a reaction you can know how many reactant you must add to obtain the amount of product you want.