Answer: the following are essential factors to be considered when choosing a solvent for crystallization
1. The crystallization solvent should not dissolve the substance to be purified at room temperature, but it should dissolve it well at the solvent’s boiling point
2. The solvent should dissolve soluble impurities well at room temperature.
3. The solvent should not dissolve insoluble impurities even at the solvent’s boiling
point.
4. The solvent must not react with the substance to be purified .
Answer:
Melamine is used for making tableware,cooking utensils, plates, plastic products etc.
Explanation:
Melamine is used to manufacture many products. How? Well melamine-formaldehyde resin, as it's full name, forms molecular structures that are molded, with heat, to take the shape of the items such as tableware.
After this chemical reaction takes place, the "left over" remains as plastic.
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And so, it is used in products such as cooking utensils, plates, plastic products etc.
Lar mass of Ca<span> = 40.08 </span>grams/mole 77.4 g Ca<span> * ( 1 </span>mole Ca<span>/ 40.08 ... n = m / M 1mol </span>Ca<span>weights 40 gmol-1 n = 77,4 / 40 = 1.93 </span>mol<span>.</span>
<span>How many mm are equal to 21 L?
1 L = </span>1000000 mm
Convert:-
1000000 × 21 = <span>21000000
21 l = </span><span>21000000 mm
</span><span>How many mg are equal to 9 g?
1 g = 1000 mg
Convert:-
9 </span>× 1000 = 9000
9 g = 9000 mg
Answer:- As per the question is asked, 35.0 moles of acetylene gives 70 moles of carbon dioxide but if we solve the problem using the limiting reactant which is oxygen then 67.2 moles of carbon dioxide will form.
Solution:- The balanced equation for the combustion of acetylene is:
From the balanced equation, two moles of acetylene gives four moles of carbon dioxide. Using dimensional analysis we could show the calculations for the formation of carbon dioxide by the combustion of 35.0 moles of acetylene.
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The next part is, how we choose 35.0 moles of acetylene and not 84.0 moles of oxygen.
From balanced equation, there is 2:5 mol ratio between acetylene and oxygen. Let's calculate the moles of oxygen required to react completely with 35.0 moles of acetylene.
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Calculations shows that 87.5 moles of oxygen are required to react completely with 35.0 moles of acetylene. Since only 84.0 moles of oxygen are available, the limiting reactant is oxygen, so 35.0 moles of acetylene will not react completely as it is excess reactant.
So, the theoretical yield should be calculated using 84.0 moles of oxygen as:
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