Answer: Sunlight passes through the atmosphere and warms the Earth's surface. ... As more greenhouse gases are emitted into the atmosphere, heat that would normally be radiated into space is trapped within the Earth's atmosphere, causing the Earth's temperature to increase.
Explanation: This keeps well life on earth so the answer is (3)
:)
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 : The correct option is, (B) Salicylic acid
Solution :
First we have to calculate the moles of salicylic acid and acetic anhydride.
Now we have to calculate the limiting and excess reagent.
The balanced chemical reaction is,
From the balanced reaction we conclude that
As, 2 moles of salicylic acid react with 1 mole of acetic anhydride
So, 0.507 moles of salicylic acid react with 
mole of acetic anhydride
The excess of acetic anhydride = 0.783 - 0.2535 = 0.5295 moles
That means the in the given balanced reaction, salicylic acid is a limiting reagent because it limits the formation of products and acetic anhydride is an excess reagent.
Hence, the limiting reagent is, salicylic acid.
The reaction involved in this problem is called the combustion reaction where a hydrocarbon reacts with oxygen to product carbon dioxide and water. The reaction of C2H5OH would be as follows:
C2H5OH + 3O2 = 2CO2 + 3H2O
To determine the number of molecules of CO2 that is formed, we need to determine the number of moles produced from the initial amount of C2H5OH and the relation from the reaction. Then we multiply avogadros number which is equal to 6.022x10^23 molecules per mole.
2.00 g C2H5OH ( 1 mol C2H5OH / 46.08 g C2H5OH ) ( 2 mol CO2 / 1 mol C2H5OH ) = 0.0868 mol CO2
0.0868 mol CO2 ( 6.022x10^23 molecules / mol ) = 5.23x10^22 molecules CO2
Answer :
(A) The number of moles of 
ions per liter is, 0.1 moles/L
(B) The number of molecules of 
ion is, 
(C) The pH of the solution will be, 4
<u>Solution for part A :</u>
First we have to calculate the pOH of the solution.
As we know that,
Now we have to calculate the moles of ion per liter.
![pOH=-\log [OH^-]\\\\1=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D%5C%5C%5C%5C1%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=0.1moles/L](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D0.1moles%2FL)
<u>Solution for part B :</u>
First we have to calculate the ion concentration.
![pH=-\log [H^+]\\\\13=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5C13%3D-%5Clog%20%5BH%5E%2B%5D)
![[H^+]=10^{-13}moles/L](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D10%5E%7B-13%7Dmoles%2FL)
Now we have to calculate the number of molecules of ion
As, 1 mole contains 
number of molecules of ion
So, 
moles contains 
number of molecules of ion
<u>Solution for part C :</u>
![pH=-\log [H^+]\\\\pH=-\log (1\times 10^{-4})](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D%5C%5C%5C%5CpH%3D-%5Clog%20%281%5Ctimes%2010%5E%7B-4%7D%29)
