Pure substance element I think
Answer:
25.2°C
Explanation:
Given parameters:
Energy applied to the water = 1000J
Mass of water = 50g
Final temperature = 30°C
Unknown:
Initial temperature = ?
Solution:
To solve this problem, we use the expression below:
H = m c Ф
H is the energy absorbed
m is the mass
c is the specific heat capacity
Ф is the change in temperature
1000 = 50 x 4.184 x (30 - initial temperature )
1000 = 209.2(30 - initial temperature)
4.78 = 30 - initial temperature
4.78 - 30 = - initial temperature
Initial temperature = 25.2°C
Answer:
It basically messes up the results
Explanation:
Pen ink consists of resins, pigments and other colouring dyes dissolved in appropriate solvents like propylene glycol, propyl alcohol and some other ethers. If the ball point pen is used to mark on the chromatography paper then these pigments will also move along with the solvent and interfere with the spots of our analyte.
If you use a ball point pen when doing a chromatogram, then the ink would separate as it is a mixture and run down the paper.
Graphite, or pencil lead however, is not an organic material and therefore will not be affected by common organic solvents used for thin-layer chromatography. Pen ink on the other hand will be readily absorbed by the solvent and will move up the plate.
