Ce procent de impuritati contine un minereu de siderit, daca din 1500kg minereu s-au obtinut 700kg fier 90% ?
2 answers:
Answer:
It has 12.84% of impurity
Explanation:
You obtained 700 kg 90% purity of Fe, so you have:
Those 630 kg are the mass of Fe contained in the original sample of 1500 kg in the from of Siderit.
The other substeances that aren't Siderit in the sample can be considered impurities.
Siderit:
The mass of siderit:
Percentaje of impurity:
You might be interested in
The question is incomplete, here is the complete question:
At elevated temperature, nitrogen dioxide decomposes to nitrogen oxide and oxygen gas
The reaction is second order for with a rate constant of
at 300°C. If the initial [NO₂] is 0.260 M, it will take ________ s for the concentration to drop to 0.150 M
a) 1.01 b) 5.19 c) 0.299 d) 0.0880 e) 3.34
<u>Answer:</u> The time taken is 5.19 seconds
<u>Explanation:</u>
The integrated rate law equation for second order reaction follows:
where,
k = rate constant =
t = time taken = ?
[A] = concentration of substance after time 't' = 0.150 M
= Initial concentration = 0.260 M
Putting values in above equation, we get:
Hence, the time taken is 5.19 seconds