Answer:
The answer to your question is below
Explanation:
Trial 1 Trial 2
mass of Mg 0.255 g 0.353 g
mass of MgO 0.418 g 0.576 g
Chemical reaction
2Mg(s) + O₂(g) ⇒ 2MgO(s)
Question 1.
Atomic mass of Mg = 24.31 x 2 = 48.62 g
Molecular mass of MgO = 2(24.31 + 16) = 80.62 g
Trial 1
48.62 g of Mg ----------------- 80.62 g of MgO
0.255 g ---------------- x
x = (0.255 x 80.62)/48.62
x = 0.422 g of MgO
Trial 2 48.62 g of Mg ----------------- 80.62 g of MgO
0.353 g ---------------- x
x = (0.353 x 80.62)/48.62
x = 0.585 g of MgO
Question 2
Trial 1
Percent yield = 0.418/0.422 x 100 = 99%
Trial 2
Percent yield = 0.576/0.585 x 100 = 98.5%
Question 3
Average = (99 + 98.5)/2
= 98.75%
Hygroscopic nature of NaOH is the main reason for the lower concentration of the sodium hydroxide in the solution.
<u>Explanation:</u>
- It is a well known fact that Sodium hydroxide pellets are hygroscopic in nature, which clearly means that the sodium hydroxide pellets absorbs moisture from the air, so that it becomes deliquescent.
- When the NaOH crystals are weighed, the crystals absorb moisture from the surroundings, and so the weight of the crystals may change, so the concentration of the solution was lower than the required one.So it is not possible to prepare NaOH solution under normal room temperature.
- So, while preparing the solution of NaOH we have to be more careful.
Answer:
In its pure form, it is a very pale blue liquid, slightly more viscous than water. Hydrogen peroxide is the simplest peroxide (a compound with an oxygen–oxygen single bond).
Oxidation half reaction is written as follows when using using reduction potential chart
example when using copper it is written as follows
CU2+ +2e- --> c(s) +0.34v
oxidasation is the loos of electron hence copper oxidation potential is as follows
cu (s) --> CU2+ +2e -0.34v
