<span>[Cu(NH3)4]2+ forms a blue solution. When concentrated HCl is added to this solution, what color will the solution change to yellow.
Reason:
When conc. HCl is added to the solution containing </span>[Cu(NH3)4]2+, Cl- ions will replace NH3 and form [Cu(Cl)4]2- complex. This can be understood for the following reaction:
[Cu(NH3)4]2+ + Cl- ↔ [Cu(Cl)4]2- + NH3
The Cl- ion is a weak field ligand, while NH3 is a strong field ligand. Hence, Cl- will in less splitting of d-orbitals, as compared to NH3. Due to this, photons of different energies will be absorbed by these complexes, and hence they display different colours.
The pH indicators to be used are Phenolphthalein, Red cabbage, Bromthymol blue and Congo red.
<h3>What are pH indicators?</h3>
Indicators are substances which change color as the pH of a medium changes.
The common indicators and their pH range is as follows:
- Phenolphthalein - pH range of 8.3 and 10.5
- Red cabbage - pH 2 to 10
- Bromthymol blue - 6.0 to 7.6
- Congo red - 3.0 to 5.2
Therefore, the indicators to be used are Phenolphthalein, Red cabbage, Bromthymol blue and Congo red.
Learn more about pH indicators at: brainly.com/question/13779537
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Answer:
7.01 g
Explanation:
Answer:- Mass of the titanium alloy is 7.01 g, choice C is correct.
Solution:- The heat of fusion is given as 422.5 joules per gram and it also says that 2960 joules of heat is required to melt the metal completely.
The suggested equation is, Q=mHf
where Q is the heat energy, m is the mass and Hf is the heat of fusion.
Since, we are asked to calculate the mass, the equation could be written as:
m=q/H5
Let's plug in the values in it:
m= 2960J/ 422.5j/g
m = 7.01 g
So, the mass of the titanium alloy is 7.01 g, choice C is correct.
