Answer:
Both K+ and NO3- concentrations are halved
Explanation:
Since the reaction is
K₂Cr₂O₇ + Pb(NO₃)₂ 2K(NO₃) + <u>PbCr</u>₂<u>O</u>₇
knowing that K+ and NO3- are spectator ions, their concentration do not change due to reaction but it will change due to the mixing of volumes of the reactants since we are mixing volumes of different concentrations.
for K+ initially we have:
c K+ initial = 0.25 M
c K+ final = n/ V = C i * Vin / Vfinal = 0.25 M * 100 ml / 200 ml = 0.125 M
the 200 ml comes from mixing the 100 ml of Pb(NO₃)₂ and 100 ml of K₂Cr₂O₇ ( assuming that the volume of the precipitate is insignificant relative to the solution , it does not occlude a significant portion of the saturated solution and assuming that any volume contraction/expansion due to non ideal behaviour of the solution is negligible)
the same happens with NO3- ,therefore its concentration is also halved
It is a covalent bond due to the fact that both atoms are sharing valence electrons with each other.
Answer:
area where it's Summertime and tropical areas
Explanation:
Answer 1: The electron is a subatomic particle that has a negative charge. Electron cannot be sub-divided further. An electron has a mass that ia ~ 1/1836 that of the proton.
The positron is also refereed as an antielectron. The positron has the charge of +1e, a spin of 1⁄2. The similarity between positron and electron is that they have same mass.
Answer 2: <span>Positron decay occurs in nuclei having heavy mass. Positron emission decreases proton number relative to the neutron number. Positron also exhibits nuclear transmutation thereby producing an atom of a different element, as compared to parent element,. Them atomic number of daughter element is less as compared to parent element by 1.
Example: </span><span><span>23 12</span>Mg </span><span>→ </span><span><span>23 11</span>Na </span><span> + </span><span>e+ </span><span>+ energy
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Answer 3: </span><span>Electron capture is also referred as </span>K-electron capture. It <span>involves absorption of energy, thereby resulting in loss of electron usually from K or L shell. In this process,following thing occurs simultaneously
i) a nuclear proton present in nuclei changes to a neutron, after reacting with an electron which falls into the nucleus from one of its orbitals (preferentially from K or L)
2) Emission of an electron neutrino.
Following is an example of K-electron capture.
7 4Be + 0 -1e </span>→ 7 3Li + energy
Answer 4: Following are the distinct features of <span>transmutations caused by positron emissions and electron capture.
i) Positron: </span><span>A proton get converted into neutron due to radio-active process. This process results in the emission of positron and neutrino. The<span> process results in decrease in atomic number by one unit, and however atomic mass number remains unchanged.
ii) Electron capture: </span></span><span>A electron from the low energy level (K-shell or L-shell) falls into the nucleus. Due to this proton is converted into neutron. During this process, neutrino is emitted from the nucleus. As seen in positron emission, t<span>he atomic number goes down by one unit, but atomic mass number remains unchanged.</span></span>
Balanced chemical reaction: 2KClO₃ → 2KCl + 3O₂.
Potassium is metal from first group of Periodic table of elements, it has always oxidation number in compound +1.
Chlorine in the reactant state has oxidation number +5 (+1 + x + 3 · (-2) = 0) and it is reduced to -1 (+1 + x = 0) in the product state.
Oxygen in the reactant state has oxidation number -2 (+1 + 5 + 3 · x = 0) and it is oxidized to 0 (in molecule of oxygen) in the product state.
