Potassium is not found free in nature but is found in the form of potash. Potash is the ore of potassium and this ore is mined from deep down the earth or can sometimes be found on the surface. Potash was mostly formed as sea water receded and left deposits.
Potash is usually in the form of potassium salts such potassium chloride and potassium sulphate. The potash is mined then taken to the factory where it is crushed and purified by removing such impurities as clay.
The now purified potassium salts are subjected to a process called electrolysis where potassium metal is obtained from its salt.
B. The surface of a silver cup turns black when it is exposed to air.
Answer:
The yeast respired aerobically
Explanation:
The expectation here was that the yeast was going to put the sugar in the grape juice through fermentation, which is an anaerobic process that results in alcohol as one of the products. However since no alcohol was found in this particular example, it is fair to assume that maybe there was oxygen in teh muxture and therefore the yeast respired aerobically, producing water and carbon dioxide as products.
Magnesium Peroxydisulphate with formula of MgS₂O₈.
<h3><u>Explanation:</u></h3>
The question clearly stands on the concept of molarity and atomic weights.
The atomic weight of magnesium = 24.
The atomic weight of sulphur = 32.
The atomic weight of oxygen = 16.
The amount of magnesium present = 0.248 g
The amount of sulphur present = 0.665 g.
The amount of oxygen present = 1.31g.
So, moles of magnesium present = 0.01 moles.
Moles of sulphur present = 0.02 moles.
Moles of oxygen present = 0.08 moles.
So, mole ratio of the compound as magnesium : sulphur : oxygen = 1:2:8.
So the compound is Magnesium Peroxydisulphate with formula of MgS₂O₈.
