What are the four important steps needed to obtain accurate meting points on a mel-temp?

a)grind the sample some.

b)grind the sample into a fine powder.

c)put the smallest amount you can see in a capillary tube.

d)fill the capillary tube with about 3mm of powder

e)set the voltage to rise quickly to 20 degree below the expected temperature, then re adjust so the temp rises at 2 degree per minute.

f)set the voltage to rise quickly to 20 degree below the expected temperature, then re adjust so the temp rises at 10 degree per minute.

g)record the temp at which liquid first appears and the temp at which the last crystal disappears.

h)record the temp at which the sample completely melts and the temp when it boils.

(b)

(d)

(e)

(g)

Explanation:

The four (4) important steps that are needed to obtain an accurate melting point is given as;

•First is Grinding: Grind the sample into fine powder.

•Second is Filling: Fill the capillary tube with about 3mm of powder

•Third is Adjusting the temperature: Set the voltage to rise quickly to 20° below the expected temperature, then re-adjust so the temperature rises at 2° per minute.

•Lastly is Observation and recordings: Record the temperature the temperature at which liquid first appears and the temperature at which the last crystal disappears.

I hope this helps, cheers.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.