Answer is: a) in the presence of a base.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions.
Acid-base indicators are usually weak acids or bases and they are chemical detectors for hydrogen or hydronium cations.
Example for acid-base indicator is phenolphthalein (molecular formula C₂₀H₁₄O₄).
When solution turns phenolphthalein pink, it means it is basic (pH>7).
Answer:
b. the layer of oxide formed on statues made of metal
Explanation:
Chemical weathering is a process whereby rocks are disintegrated or weathered causing a chemical reaction thereby leading to change in the parent rock constituents .
In chemical weathering a new substance is usually formed after the weathering takes place.
From the question the layer of statue made by metal will likely form oxides of those metals. Example Silver will react with oxygen to form an entirely new substance like silver(i)oxide.
From the calculation, the pH of the solution after dilution is 3.
<h3>What is the pH?</h3>
The pH is the hydrogen ion concentration of the solution. Now we know that;
C1 = 0.010 m
V1 = 10.0 ml
V2 = 10.0 ml + 100.0 ml = 110 ml
C2 = ?
C1V1 = C2V2
C2 = C1V1 /V2
C2 = 0.010 m * 10.0 ml / 110 ml
C2 = 0.00091 M
pH = -log[0.00091 M]
pH = 3
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Answer: Option (a) is the correct answer.
Explanation:
Ionic salts are defined as the salts which tend to contain ionic bonds as there occurs transfer of electrons between its combining atoms.
So, when an ionic salt melts or it is dissolved in water then it will dissociate into its respective ions and as electricity is the flow of electrons or ions. Hence, this salt is then able to conduct electricity.
As covalent compounds are insoluble in water so, they do no dissociate into ions. Hence, they do not conduct electricity.
Similarly, metallic and network solids do not dissociate into ions either when melted or dissolved in water. Therefore, they also do not conduct electricity.
Thus, we can conclude that when a white crystalline salt conducts electricity when it is melted and when it dissolves in water then this bond is of ionic type.
Answer:
The answer is "
"
Explanation:
Given:
Molarity= number of moles
because it is 1 Liter
therefore,
it takes 20 mL of Tris.
So, take 
