5.7% KCl is 94.3 % water.
Therefore, for 1000 g of water the mass of KCl will be (1000× 5.7)/94.3 = 60.445 grams.
1 mole of KCl is equal to 74.55 g,
therefore, 60.445 g will be 60.445/74.55 = 0.8108 mole of KCl
Hence, 0.8108 moles of KCl should release twice that number of moles 1.6216 moles ions.
Having 1.6216 moles of KCl ions dissolved in 1000g of water, gives us 1.6216 molar if solution.
Using the freezing point depression constant of water.
dT = Kf (molarity)
dT = (1.86 C/ molar) (1.6216 m)
dT = 3.016 C drop in freezing point
Therefore, it should freeze at - 3.016 Celsius
Answer:
The mass of iron needed to react with the oxygen is 70 g.
Explanation:
The balanced chemical reaction between iron and oxygen is given as;
4Fe + 3O₂ ----------> 2Fe₂O₃
Molecular mass of 3O₂: 3(16 x 2) = 96 g
Molecular mass of 4Fe: 4(56) = 224 g
96 g of O₂ ---requires--------> 224 g of Fe
30 g of O₂ -------requires--------->? Fe
= (30 x 224) / 96
= 70 g
Therefore, the mass of iron needed to react with the oxygen is 70 g.
"the same";
One mole of any given thing is 6 * 10²³ of it;
One mole of H₂O is 6 * 10²³ molecules;
One mole of O₂ is also 6 * 10²³ molecules;
Therefore for both substances, there are the same number of molecules.
Answer:
Explanation:
1. Convert decagrams to grams
2. Convert grams to decigrams
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