Answer:
0.09375M
Explanation:
There are two methods of going about this, either we use dilution formula (easiest and fastest) or we solve through molarity.
Using dilution formula,
C2 (H2SO4) = ?
C1 (NaOH) = 0.25M
V2 (H2SO4) = 20cm³
V1 (NaOH) = 15cm³
However we can solve using molarity method
Equation of reaction =
2NaOH + H2SO4 ====》 Na2SO4 + 2H2O
O.25M of NaOH = 1000cm³
X moles = 15cm³
X = (0.25 * 15) / 1000
X = 0.00375 moles is present in 15cm³ of NaOH
From equation of reaction,
2 moles of NaOH requires 1 mole of H2SO4
Therefore
0.00375 / 2 = 0.001875 moles is present in H2SO4
From the reaction,
0.00187 moles of H2SO4 = 20 cm³
X moles = 1000cm³
X = (0.00187*1000) / 20 = 0.09375M
Answer: Magnesium
Explanation:
Galvanic cell is a device which is used for the conversion of the chemical energy produces in a redox reaction into the electrical energy.
The standard reduction potential for magnesium and zinc are as follows:
![E^0_{[Mg^{2+}/Mg]}= -2.37V](https://tex.z-dn.net/?f=E%5E0_%7B%5BMg%5E%7B2%2B%7D%2FMg%5D%7D%3D%20-2.37V)
![E^0_{[Zn^{2+}/Zn]}=-0.76V](https://tex.z-dn.net/?f=E%5E0_%7B%5BZn%5E%7B2%2B%7D%2FZn%5D%7D%3D-0.76V)
Reduction takes place easily if the standard reduction potential is higher (positive) and oxidation takes place easily if the standard reduction potential is less (more negative).
Here Mg undergoes oxidation by loss of electrons, thus act as anode. Zinc undergoes reduction by gain of electrons and thus act as cathode.
Thus magnesium gets oxidized.
Answer:
Elements in the periodic table are arranged from atomic number, increasing as you move more towards the right direction.
The thing that governs whether a reaction is exothermic is the energy given out / used up to break / form the bonds in the reaction.
<span>When two substances react, the bonds in those substances first break up, releasing energy, before re-forming in a different way, taking in energy. The nature of the bonds that are broken up and reformed determines whether more energy is given out (exothermic) or taken in (endothermic)</span>
