Answer:
A. manganese change from +7 to +2
Explanation:
Reduction means a gain of electrons, which means the oxidation number will go down or the charge goes down basically or become more negative charge. On the left, Mn has +7 in MnO4-. On the right, it has 2+, so it has been reduced.
Answer:
pH = 3.37
Explanation:
A weak acid as lactic acid in a solution with sodium lactate (Its conjugate base) produce a buffer. The pH of this buffer is obtained using H-H equation:
pH = pKa + log [A-] / [HA]
<em>Where pH is the pH of the buffer,</em>
<em>pKa is 3.86</em>
<em>And [] could be taken as the moles of A- = Sodium lactate and HA = Lactic acid.</em>
<em />
Moles A-:
40.0mL = 0.0400L * (0.75mol / L) = 0.030 moles A-
Moles HA:
75.0mL = 0.0750L * (1.25mol / L) = 0.09375 moles HA
Replacing:
pH = 3.86+ log [0.030 moles A-] / [0.09375 moles HA]
<h3>pH = 3.37</h3>
<em />
Answer:
52.99 kPa
Explanation:
Initial volume V1 = 2.7 L
Initial Pressure P1 = 78.5 kPa
Final Volume V2 = 4.0L
Final Pressure P2 = ?
Temperature is constant
The relationship between these quantities is given by the mathematical expression of Boyles law. This is given as;
V1P1 = V2P2
P2 = V1P1 / V2
P2 = 2.7 * 78.5 / 4.0
P2 = 52.99 kPa
You have to start listing from the bottom :
3. Secondary Consumers
2. Primary Consumers
1. Producer