Answer:
Close to the calculated endpoint of a titration - <u>Partially open</u>
At the beginning of a titration - <u>Completely open</u>
Filling the buret with titrant - <u>Completely closed</u>
Conditioning the buret with the titrant - <u>Completely closed</u>
Explanation:
'Titration' is depicted as the process under which the concentration of some substances in a solution is determined by adding measured amounts of some other substance until a rection is displayed to be complete.
As per the question, the stopcock would remain completely open when the process of titration starts. After the buret is successfully placed, the titrant is carefully put through the buret in the stopcock which is entirely closed. Thereafter, when the titrant and the buret are conditioned, the stopcock must remain closed for correct results. Then, when the process is near the estimated end-point and the solution begins to turn its color, the stopcock would be slightly open before the reading of the endpoint for adding the drops of titrant for final observation.
Answer:
A student can predict Amount of calories present if she finds the mass of whole candy bar,including the wrapper.
<u>Explanation:</u>
Based on the mass of a whole candy bar a student can predict the calories contained in the candy bar. If the mass of candy bar is more than it means it has more calories and if the candy bar has less mass than it shows the presence of fewer calories.
More calories mean more sugar content in the candy bar. With sugar, the candy bar has carbohydrates also. The sugar present in the bar gives us energy.
The element in period 4 of the Periodic Table with the highest electronegativity is krypton (2.96).
Answer:
In the reaction, Fe2+ is oxidized and MnO4- is reduced (option c.)
Explanation:
MnO₄⁻ + 5Fe²⁺ + 8H⁺ ---> Mn²⁺ + 5Fe³⁺ + 4H2O
Look all, the oxidation number.
Increase the oxidation number means, oxidation.
Decrease the oxidation number means, reduction.
Fe²⁺ → Fe³⁺ is increasing, the ox. number. Fe is oxidizing.
In MnO₄⁻, the Mn acts with +7, so in Mn²⁺ has decrease the ox. number.
Mn has reducted.
Answer: 79.6 g
mwof 02 is 16 and mw of H2O is 18.
