Answer:
percentage of water = 18.76%
Explanation:
A chemist has a sample of hydrated Li2SiF6 and it weighs 0.4813 grams.
The overall weight of the compound is 0.4813 grams.
weight of hydrated sample = 0.4813 grams.
weight of anhydrous compound = 0.391 grams
percentage weight of water = mass of water/mass of the hydrated compound × 100
mass of water = mass of hydrated compound - mass of anhydrous compound
mass of water = 0.4813 - 0.391 = 0.0903 grams.
percentage of water = 0.0903/0.4813 × 100
percentage of water = 9.03/0.4813
percentage of water = 18.761687097
percentage of water = 18.76%
well, without the article, I'm guessing the main idea is about the Great Wall of China
1.17×6×1023
Wich equals 7.02×1023
Your final answer is 7.02×1023
Reaction between mercury (ii) sulfide with Calcium oxide is as shown;
4 HgS +4 CaO = 4 Hg + 3 CaS + CaSO4
The molar mass of HgS is 232.66 g/mol
The number of moles = 31.28/232.66
= 0.1344 moles
The mole ratio of HgS : CaO is 1: 1
Therefore, the number of moles of Calcium oxide is 0.1344 moles
1 mole of CaO Contains 56 g/mol
Thus, the mass of CaO is 56 g/mol
= 0.1344 moles × 56 g/mol
= 7.5264 g
