Answer:
the unknown substance is a protein
Explanation:
The biuret test is one of the tests for proteins. It can be used to detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed leading to the appearance of a violet color.
Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides. It involves the formation of a purple (violet) complex of Copper salts in alkaline solution.
Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein
Answer:
Wt. Avg. Atomic Weight => 63.35457 amu
Explanation:
Given Isotopic %Abundance fractional Wt Avg
At. Mass (amu) abundance contribution
Cu-63 62.93 69.09 0.6909 43.4783
Cu-65 64.9278 20.0668 0.200668 20.0668
Wt Average of all isotopes = ∑Wt Avg Contributions
= 43.4783 amu + 20.0668 amu = 63.35457 amu
Answer:
Record players
Explanation:
In a record player, a stylus vibrates as it follows a spiral groove cut into the surface of the rotating record.
The vibrations (analogue) are converted into electrical signals and fed into an amplifier to produce the sounds you hear
Fiber optic cables, Wi-Fi devices, and flat screen TVs use digitized signals to encode and transmit information
The chemical reaction would be written as follows:
2Al + 3Cl2 = 2AlCl3
We are given the amount of aluminum to be used in the reaction. This will be the starting point of the calculations. We do as follows:
19.0 g Al ( 1 mol / 29.98 g ) ( 2 mol AlCl3 / 2 mol Al ) = 0.63 mol AlCl3
D will because water just turns from liquid to a gas by adding heat. That is a physical change. The other equations are chemical changes.
