Read the descriptions below of two substances and an experiment on each. Decide whether the result of the experiment tells you t
he substance is a pure substance or a mixture, if you can . Sample A is 100.mL of a clear liquid. The density of the liquid is measured, and turns out to be 0.77/gmL. The liquid is then heated in a flask until it boils. The vapor that rises off the boiling liquid is collected for 10 minutes and cooled until it condenses into a separate beaker. The density of the liquid that remains in the flask is then measured, and turns out to be 1.04/gmL.
Sample B is 100.g of a coarse grey powder with a faint unpleasant smell. 15.g of the powder are dissolved in ethanol. 0.5mg of the resulting black solution is carefully dropped onto a thick sheet of paper laid flat in a tray. After 30 minutes the initial round black stain has spread out and faded in color to a deep purple. Additionally, there is a dark green ring surrounding the inner stain.
a. Is sample A made from a pure substance or a mixture?
b. If the description of the substance and the outcome of the experiment isn't enough to decide, choose "can't decide.
c. Is sample B made from a pure substance or a mixture?
d. If the description Of the substance and the outcome of the experiment isn't enough to decide, Choose "can't decide.
For sample A, we were told that the initial density of the solution is 0.77/gmL. After distillation, the liquid left has a density of 1.04/gmL. Apparently, A is a mixture of liquids.
As for sample B, the spread of the chromatogram resulting in different colours show that the sample B is not pure. It is a mixture of substances. A pure sample will yield only a single spot.
frequency it the measure of the wave length. The measure of the peaks and troughs is how you measure the frequency. the distance between these is the wave length.
Temperature and thermal energy are in a direct proportion which means that if temperature of a substance increases, its thermal energy also increases and vice versa.
A) gases; solids B) metals; nonmetals C) nonmetals; metals <span>D) reactive; nonreactive </span> I think the correct answer is option B. The stair-step line between the pink squares and the yellow squares separates the metals from the nonmetals. Hope this helps.
