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:
The answer to your question is 0.54M
Explanation:
Data
Final concentration = ?
Concentration 1 = 0.850 M
Volume 1 = 249 ml = 0.249 l
Concentration 2 = 0.420 M
Volume 2 = 0.667 M
Process
1.- Calculate the number of moles in both solutions
Number of moles 1 = Molarity 1 x Volume 1
= 0.850 x 0.249
= 0.212
Number of moles 2 = Molarity 2 x Volume 2
= 0.420 x 0.667
= 0.280
Total number of moles = 0.212 + 0.280
= 0.492
2.-Calculate the final volume
Final volume = Volume 1 + Volume 2
Final volume = 0.249 + 0.667
= 0.916 l
3.- Calculate Molarity
Molarity = 0.492 / 0.916
Molarity = 0.54
Answer:
dissolving sugar in water
burning a candle
Explanation: these both have chemical and physical changes happening to them.
Answer: A. -396 kJ
Explanation:
The standard enthalpy of formation or standard heat of formation of a compound is the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states.
Reversing the reaction, changes the sign of 
On multiplying the reaction by 2, enthalpy gets multiplied by 2:
Thus the enthalpy change for the reaction is -396 kJ.
