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:
Aluminium is ordinarily classified as a metal. It is lustrous, malleable and ductile, and has high electrical and thermal conductivity. Like most metals, it has a close-packed crystalline structure and forms a cation in an aqueous solution.
Answer: The partial pressure of the dry oxygen is 742 torr
Explanation:
Dalton's Law of Partial Pressure states that the total pressure exerted by a mixture of gases is the sum of partial pressure of each individual gas present. Thus 
Given; Total pressure = 762 torr
partial pressure of water = 19.8 torr
partial pressure of dry oxygen = ? torr
Total pressure = partial pressure of water + partial pressure of dry oxygen
762 torr = 19.8 torr = partial pressure of dry oxygen
partial pressure of dry oxygen = 742 torr
The partial pressure of the dry oxygen is 742 torr