When a magnesium wire is dipped into a solution of lead (II) nitrate, a black deposit forms on the wire. Which of the following
can be concluded from this observation?
(A) The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
(B) Mg(s) is less easily oxidized than Pb(s).
(C) An external source of potential must have been supplied.
(D) The magnesium wire will be the cathode of a Mg/Pb cell.
(E) Pb(s) can spontaneously displace Mg2+(aq) from solution.
...
(A) The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
(B) Mg(s) is less easily oxidized than Pb(s).
(C) An external source of potential must have been supplied.
(D) The magnesium wire will be the cathode of a Mg/Pb cell.
(E) Pb(s) can spontaneously displace Mg2+(aq) from solution.
...
1 answer:
Answer:The standard reduction potential, Eo , for Pb2+(aq) is greater than that for Mg2+(aq).
Explanation:
Metals are usually arranged in an order of reactivity called activity series. Metals that are high up in the series are good reducing agents with very low (very negative) reduction potentials. Metals with greater (less negative) reduction potentials are found lower in the series. In the image attached, elements were arranged according to their reducing ability. Magnesium is very electro positive hence it is a better reducing agent with a lesser standard reduction potential than lead(refer to the image for numerical values of standard reduction potentials). Hence it displaces lead from solution and the elemental lead deposits on the wire.
You might be interested in
Answer:
Ionization energy of the metal and electron affinity of the nonmetal
Explanation:
An ionic bond is formed when a metal transfers electrons to a nonmetal.
M· + A ⟶ M⁺ + ·A⁻
The two main factors affecting this process are the
- Ionization energy of the metal
- Electron affinity of the nonmetal
1. Ionization energy
The lower the ionization energy of the metal, the more likely it is able to donate an electron.
2. Electron affinity
The higher the electron affinity of the nonmetal, the more likely it is to accept an electron,
3. Periodic trends
(a) Ionization Energy
Ionization energy increases from bottom to top and from left to right in the Periodic Table.
Thus, the atoms with the lowest ionization energy are in the lower left corner of the Periodic Table.
(b) Electron affinity
Electron affinity increases from bottom to top and from left to right in the Periodic Table.
Thus, the atoms with the highest electron affinity are in the upper right corner of the Periodic Table.
Answer:
0.683 mol
46.3 g
Explanation:
There is some info missing. I think this is the original question.
<em>Boron trifluoride gas is collected at 21.0 °C in an evacuated flask with a measured volume of 50.0 L. When all the gas has been collected, the pressure in the flask is measured to be 0.330 atm. Calculate the mass and number of moles of boron trifluoride gas that were collected. Round your answer to 3 significant digits.</em>
<em />
Step 1: Convert the temperature to the Kelvin scale
We will use the following expression.
K = °C + 273.15
K = 21.0°C + 273.15
K = 294.2 K
Step 2: Calculate the moles of boron trifluoride gas
We will use the ideal gas equation.
Step 3: Calculate the mass of boron trifluoride gas
The molar mass of BF₃ is 67.81 g/mol.