1. This can be due to the dissolving of the solid in liquid and form a solution.
Dissolving is a physical property because dissolving doesn't form new substances and the chemical composition of the solid is not changed.
The color building up over the time can be due to the rate of dissolving of the solid and amount of particles have been dissolved.
Example:
- Dissolving of CuSO₄ solid in water.
- This develops a blue color.
2. This can be due to the chemical reaction between the solid and liquid.
Chemical reaction is a chemical property because from reacting substances new substances can be formed which the chemical formula is different from initial substances.
The color building up over the time can be due to the rate of the reaction and the amount of reactants.
Example:
- The reaction between calcium metal with water.
- The color of Ca(OH)₂ is white color.
- Reaction is
Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g)
The Answer for this question is : A
1 & 2
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 is A
The kinetic theory is used to explain the behaviour of gases.
One of the assumptions states that "a gas is composed of a large number of identical molecules moving at different speeds".
To find the mole of a substance, you take the mass divided by the molar mass of that substance~
