The answer is: II.The endpoint is recorded when the solution is dark red in color rather than light pink.
The endpoint is the point at which the indicator changes colour in a colourimetric titration and that is point when titration must stop.
Phenolphthalein is colorless in acidic solutions and pink in basic solutions. If this indicator change color to dark red, more base is added and endpoint is not accurate.
If the the acid is spilled before titration, that does not make endpoint wrong and molar mass can be calculated.
In this example we can take acetic acid as carboxylic acid; basic salt sodium acetate CH₃COONa is formed from the reaction between weak acid (in this example acetic acid CH₃COOH) and strong base (in this example sodium acetate NaOH).
Balanced chemical reaction of acetic acid and sodium hydroxide:
CH₃COOH(aq) + NaOH(aq) → CH₃COONa(aq) + H₂O(l).
Neutralization is is reaction in which an acid (in this example vinegar or acetic acid CH₃COOH) and a base react quantitatively with each other.
Answer:
The correct option is: When the amount of acid and base are equal
Explanation:
Titration is an analytic method that is used to determine the concentration of an<em> unknown solution</em>, called <em>titrand</em>.
In this method, standard solution of known concentration, called <em>titrant</em>, is taken in the burette and added drop-wise to the titrand solution in the flask, until the endpoint is reached.
In case of an acid-base titration, a <em>pH indicator</em> is used, which changes the color of the solution when the endpoint is reached.
<u>The </u><u>endpoint</u><u> indicates the </u><u>equivalence point</u><u> of an acid-base titration, where the </u><em><u>concentration of the acid and base is equal</u></em><u>. </u>
<u>Therefore, the </u><u>correct option</u><u> is: </u><u>When the amount of acid and base are equal</u>
Answer:
the ability to breed successfully
Explanation:
Physical properties help identifying a substance and how it changes.
For example: if a substance crushes easily that means it has a low density, but if it’s hard and doesn’t crush easily, that means it has a strong high density.
And eventually the substance would not end up forming a new substance.
Look at the picture below to understand more about physical changes.
Answer: 1Ca + 2O + 2H
Explanation:
Ca is 1 since there is no subscript
O and H each have 2 because the subscript 2 is outside the parenthesis so you multiply their subscript (1) by 2
