5.6L of O2 means we have 0.25 moles of O2.
As, 1 mole has 6.023*10^23 molecules,
0.25 moles of O2 will have 0.25*6.023*10^23 molecules=1.50575*10^23 molecules
and as 1 molecule of O2 has 2 atoms, so, 1.50575*10^23 molecules will have 2*1.50575*10^23 atoms=3.0115*10^23 atoms of O.
Answer: Sodium + water → hydrogen gas + sodium hydroxide (aq) + heat [(aq) means “dissolved in water”. It stands for “aqueous”.] If we boil off the water, we will be able to see the sodium hydroxide crystals. The sodium hydroxide is one of the two new substances produced by this chemical change.
Answer:
43 mole
Explanation:
Given data:
Number of atoms of Li = 2.6× 10²⁵ atoms
Number of moles = ?
Solution:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance. The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
2.6× 10²⁵ atoms × 1 mole / 6.022 × 10²³ atoms
0.43 × 10² mole
43 mole
<span>Scientific endeavors is basically all the things that would contribute to the process of achieving a certain scientific knowledge, from the initial observation, up to the point until we can hold that certain thing as acknowledged truth. So,
All scientific endeavors are supported by evidence.
All scientific endeavors are a systemic process.
All scientific endeavors involve observation.
All scientific endeavors involve experimentation.
All scientific endeavors involve the collection of information.
</span>
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.