Answer:
Rb
Explanation:
Ionization energy is defined required energy to eliminate or remove an electron from an ion or atom.
From the given elements Rb or Rubidium has the lowest ionization energy as it has lowest shielding effect, so it easy to remove electron from it's shell.
The ionization energy generally decreases from top to bottom in groups due to lower shielding effect and outer electrons are loosely packed so easy to remove and increases from left to right across a period because of valence shell stability.
Rubidium has atomic number 37 and lies below than other given elements and also placed in the left side in the periodic table.
Hence, the correct option is Rb
Answer:
magnesium metal
Explanation:
According to the redox reaction equation, six electrons were transferred hence n=6 and F= Faraday's constant 96500C. ∆G° is given hence E°cell can easily be calculated as follows:
From ∆G°= -nFE°cell
E°cell= -∆G°/nF= -(-411×10^3/96500×6)
E°cell= 0.7098V
But for Al3+(aq)/Al(s) half cell, E°= -1.66V from standard table of reduction potentials.
E°cell= E°cathode- E°anode but Al3+(aq)/Al(s) half cell is the cathode
Hence
E°anode=E°cathode - E°cell
E°anode= -1.66-0.7098= -2.37V
This is the reduction potential of Mg hence the anode material was magnesium metal
Cu (s) + 2AgNO3 ---> 2Ag + Cu(NO3)2
=13.5 moles Silver Nitrate
Answer:
(a) rate = 4.82 x 10⁻³s⁻¹ [N2O5]
(b) rate = 1.16 x 10⁻⁴ M/s
(c) rate = 2.32 x 10⁻⁴ M/s
(d) rate = 5.80 x 10⁻⁵ M/s
Explanation:
We are told the rate law is first order in N₂O₅, and its rate constant is 4.82 x 10⁻³s⁻¹ . This means the rate is proportional to the molar concentration of N₂O₅, so
(a) rate = k [N2O5] = 4.82 x 10⁻³s⁻¹ x [N2O5]
(b) rate = 4.82×10⁻³s⁻¹ x 0.0240 M = 1.16 x 10⁻⁴ M/s
(c) Since the reaction is first order if the concentration of N₂O₅ is double the rate will double too: 2 x 1.16 x 10⁻⁴ M/s = 2.32 x 10⁻⁴ M/s
(d) Again since the reaction is halved to 0.0120 M, the rate will be halved to
1.16 x 10⁻⁴ M/s / 2 = 5.80 x 10⁻⁵ M/s
Answer:
It increases when a catalyst is added.
Explanation:
The following factors control reaction rates:
1. Nature of reactants
2. Concentration of the reactants or pressure of gaseous
3. Temperature
4. Presence of catalyst
5. Sunlight
The addition of a foreign body to a reaction may influence the speed of the reaction. If a foreign body increases the rate of reaction, it is a called a positive catalyst or simply a catalyst. A negative catalyst is called an inhibitor.
A catalyst is a substance that is introduced into a chemical reaction to change the rate of the reaction without itself being affected at the end of the reaction.
Catalysts helps to reduce reaction time of many slow reactions. Most catalysts are specific in their actions and works on certain reactions or substrates.
Temperature change has a considerable effect on reaction rates since temperature is directly proportional to the average kinetic energy of reacting particles. Generally, reaction rate varies as temperature directly.
