Answer:
The facial reconstruction problem arises in various application fields like forensics, anthropology, archeology or history. In forensic science, facial reconstruction comes in the process of identification of deceased people
Explanation:
2.-> At the equivalence point, the pH = 7.00 for strong acid- strong base titrations.
3.-> A strong acid- strong base titration is performed using a phenolphthalein indicator. Phenolphtalein is chosen because it changes color in a pH range between 8.3 – 10. It will appear pink in basic solutions and clear in acidic solutions.
Iron becomes rusted especially in damp air but never in a dry air, this is one of the many unique characteristics of iron. Iron is also ductile and malleable. It is found in the seventh group of the periodic table. It has four different and unique crystalline forms and completely dissolves in dilute acids. The two chemical compounds that can be found or made from iron are the bivalent iron also known as ferrous and the trivalent iron or known as ferric compounds.
Answer:
9.0 g
Explanation:
There is some info missing. I think this is the original question.
<em>A chemist must prepare 0.9 L of sodium hydroxide solution with a pH of 13.40 at 25°C. He will do this in three steps: Fill a volumetric flask about halfway with distilled water. Weigh out a small amount of solid sodium hydroxide and add it to the flask. Fill the flask to the mark with distilled water. Calculate the mass of sodium hydroxide that the chemist must weigh out in the second step. Round your answer to 2 significant digits.</em>
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Step 1: Calculate the pOH
We use the following expression.
pH + pOH = 14.00
pOH = 14.00 - pH = 14.00 - 13.40 = 0.60
Step 2: Calculate [OH⁻]
We use the following expression.
pOH = -log [OH⁻]
[OH⁻] = antilog -pOH = antilog -0.60 = 0.25 M
Step 3: Calculate [NaOH]
NaOH is a strong base that releases 1 OH⁻. Then, [NaOH] = 0.25 M
Step 4: Calculate the mass of NaOH
The molar mass of NaOH is 40.00 g/mol. The mass required to prepare 0.9 L of a 0.25 M solution is:
Answer:
It will be an unstable system because it will not be able to recover from the disturbance.
Explanation:
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