Answer:
a. The phenolphthalein acts as a color changing indicator to signal the endpoint of the reaction.
Explanation:
Phenolphthalein is an organic substance with chemical formula
.
It is a substance commonly used in acid-base titrations to indicate the end point in the titration because phenolphthalein is colorless in acidic solutions but turns a purplish-pink color in basic solutions.
In this way it helps visually to notice when the final point of the titration has been reached.
Answer:

Explanation:
The number of valence electrons tells us the group number of the neutral atom.
The atom has 4 valence electrons.
The atom is in group 4.
Weathering breaks down rock and other material
Given:
A compound with:
Number of carbon atoms = 9
Number of double bonds = 1
A double bond between 5th and 6th carbon
A propyl group (CH2CH2CH3) branching off the 3rd carbon from the left
Try to illustrate the given and observe the formation of the atoms. Now, follow the correct IUPAC naming system. The name of the compound is
4-propyl-1-hexene
Count from the right to the left, the double bond is between the 1st and 2nd carbon, thus, 1-hexene. The propyl branches out the 4th carbon from the right, thus 4-propyl.
Answer:
0.24 M
Explanation:
Molarity = Moles solute / Liters solution
Step 1: Identify variables
400 mL = Liters solution
0.60 moles = Moles solute
Step 2: Identify conversions
1 L = 1000 mL
Step 3: Convert mL to L
400mL(1 L/1000mL) = 0.4 L
Step 4: Find molarity
M = (0.4 L)(0.60 mol) = 0.24 M