Answer:
D. You can no longer tell if your original sample contained Na+ or K+.
Explanation:
Group reagents are the reagents which are used to separate a whole group of cations from the other groups of cations.
For example, for group 1 , the group reagent is HCl and for group 5, the group reagent is ammonium carbonate.
<u>When sodium chloride and potassium carbonate is used, it means we are contaminating our sample with foreign cations which may interfere in the process of detection. Also, we will not be able to decipher whether the sample has these ions in the initial or not as we have added them.</u>
It extends 10 to 15 kilometers (6 to 10 miles) above the earth's surface depending on latitude and time of the year. The troposphere contains most of the atmosphere's water vapor.
Answer is: empirical formula is Fe₂O₃.
m(Fe) = 7,50 g.
m(iron oxide) = 10,71 g.
n(Fe) = m(Fe) ÷ M(Fe).
n(Fe) = 7,50 g ÷ 55,85 g/mol = 0,134 mol.
m(O) = m(iron oxide) - m(Fe).
m(O) = 10,71 g - 7,50 g = 3,21 g.
n(O) = 3,21 g ÷ 16 g/mol = 0,20 mol.
n(Fe) : n(O) = 0,134 mol : 0,2 mol = 2 : 3.
The answer is 71.5g of potassium sulfate
