Answer:
See explanation
Explanation:
Crystals can be made from methanol by recrystallizing the plant extract from methanol.
The methanol/water system is heated rapidly using a hot plate and the plant extract dissolves in the heating solution until a clear solution is obtained.
The solution is now cooled rapidly. The interior of the flask used for the re crystallization may even by scratched to assist the quick formation of crystals. Large crystals of plant compounds may be obtained using this method. This process should be carried out in a fume hood because of the toxicity of methanol.
Answer:
Explanation:
To solve this problem, we need to obtain the number of moles of the solute we desired to prepare;
Number of moles = molarity x volume
Parameters given;
volume of solution = 500mL = 0.5L
molarity of solution = 0.5M
Number of moles = 0.5 x 0.5 = 0.25moles
Now to know the volume stock to take;
Volume of stock = 
molarity of stock = 4M
volume = 
= 0.0625L or 62.5mL
You have molarity and you have volume. Use the formula :
Molarity(M)= Moles(N)/Liter(L) to get the solution.
450 ml= .450 L
.250 = N/.450
N=.1125 moles of NaOH.
And since you know the moles, use the molar mass to figure out the grams.
<span> (40g/mol NaOH) x (.1125 mol) =
4.5g of NaOH.
</span>
Hope it helps. Good luck on chemistry.
The heat that is required to raise the temperature of an object is calculated through the equation,
heat = mass x specific heat x (T2 - T1)
Specific heat is therefore calculated through the equation below,
specific heat = heat / (mass x (T2 - T1))
Substituting,
specific heat = 645 J / ((28.4 g)(15.5 - - 11.6))
The value of specific heat from above equation is 0.838 J/g°C.
