An abyssal plain......................................
Reaction of galvanic cell
<h3>Further explanation</h3>
Given
Redox reaction between Zn and Mg
Required
Half reaction
Potential of the cell
Solution
Zn²⁺ + 2e -> Zn E ° = -0.76 V
Mg²⁺ + 2e -> Mg E ° = - 2.37 V
The higher E ° of the cell will act as the positive pole/cathode
Electrode Zn as a cathode (reduction) and Mg as an anode (oxidation) (E ° of Zn cells is greater than Mg)
Half reaction
Cathode: Zn²⁺ + 2e ⇒ Zn E ° = -0.76 V
Anode: Mg ⇒ Mg²⁺ + 2e E ° = +2.37 V
------------------------------------------------- ----------- +
Cell reaction: Zn²⁺ + Mg ---> Zn + Mg²⁺ E ° cell = +1.61 V
The reaction occurs spontaneously in the absence of an electric current, thus including galvanic cells/voltaic cells
<u>Answer:</u> The for the reaction is -297 kJ.
<u>Explanation:</u>
Hess’s law of constant heat summation states that the amount of heat absorbed or evolved in a given chemical equation remains the same whether the process occurs in one step or several steps.
According to this law, the chemical equation is treated as ordinary algebraic expressions and can be added or subtracted to yield the required equation. This means that the enthalpy change of the overall reaction is equal to the sum of the enthalpy changes of the intermediate reactions.
The given chemical reaction follows:
The intermediate balanced chemical reaction are:
(1)
(2)
The expression for enthalpy of the reaction follows:
Putting values in above equation, we get:
Hence, the for the reaction is -297 kJ.
the molar mass of formic acid CH2O2 = 46.03 g/mol
the number of moles of HCHO2 = 0.0349 g / 46.03 g/mol
n = 7.58 × 10^-4 mol
according to the balanced chemical equation
HCHO2 + NaOH → H2O + NaCHO2
1 mol of formic acid will react with 1 mol of NaOH
so we need 7.58 × 10^-4 mol of NaOH
the molarity = 0.1500M = 7.58 × 10^-4 mol / volume
the volume = 7.58 × 10^-4 mol / 0.1500M
= 5.05 × 10^-3 L = 5.05 ml
Answer:
18.02 g/mol
Explanation:
Add the atomic mass of the parts of H2O
1.01 + 1.01 + 16 = 18.02
H H O