Answer:
Large crystals
Slowly
Explanation:
Recrystallization is a procedure used to purify an impure compound in a solvent. The concept used here is that the solubility of most of the solids increases with increase in temperature.
Recrystallization is also called as method of fractional crystallization.
After a recrystallization, a pure substance will ideally appear as a network of <u>large crystals</u>. If this is not the case, it may be worthwhile to reheat the flask and allow the contents to cool more <u>slowly</u>.
Answer:
no. of moles = measured mass of substance/ molar mass of the constituted elements
Explanation:
No. of moles of 2.0g NaCl= 2/(23+35.5) = 0.034mol
Answer: B. It is an ether because it is unable to to form a hydrogen bond, so it is less soluble than water
Explanation: Alcohols
are more soluble in water as they can form hydrogen bonding with water whereas ethers
are less soluble as they do not form hydrogen bonds with water.
For formation of hydrogen bond, the electronegative atom (F, Oand N) must be attached to hydrogen and in ethers (ROR), there is no hydrogen directly attached to electronegative oxygen atom, thus are less soluble in water.
4 x
in dL will be 4 x
<h3>Conversion from dL to cm^3</h3>
Recall that:
Deci = 
Centi = 
Thus, 1 dl = 100 ml
This means that converting from dl to
requires multiplying by
.
Applying this principle, 4 x
in dL to
will be:
4 x
x
= 4 x
Therefore, 4 x
dl will be 4 x
More on volume conversion can be found here:
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