Answer:
0.98 g of H₂
Explanation:
the balanced equation for the reaction is
Mg + 2HCl ---> MgCl₂ + H₂
molar ratio of Mg to H₂ is 1:1
number of Mg moles reacted = 12 g/ 24.3 g/mol = 0.49 mol
according to molar ratio
when 1 mol of Mg reacts 1 mol of H₂ is formed
therefore when 0.49 mol of Mg reacts - 0.49 mol of H₂ forms
therefore mass of H₂ formed = 0.49 mol x 2 g/mol = 0.98 g
mass of H₂ formed is 0.98 g
Answer : The concentration of 
ion, pH and pOH of solution is, 
, 1.05 and 12.95 respectively.
Explanation : Given,
Concentration of 
ion = 0.090 M
pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.
The expression used for pH is:
![pH=-\log [H^+]](https://tex.z-dn.net/?f=pH%3D-%5Clog%20%5BH%5E%2B%5D)
First we have to calculate the pH.
The pH of the solution is, 1.05
Now we have to calculate the pOH.
The pOH of the solution is, 12.95
Now we have to calculate the concentration.
![pOH=-\log [OH^-]](https://tex.z-dn.net/?f=pOH%3D-%5Clog%20%5BOH%5E-%5D)
![12.95=-\log [OH^-]](https://tex.z-dn.net/?f=12.95%3D-%5Clog%20%5BOH%5E-%5D)
![[OH^-]=1.12\times 10^{-13}M](https://tex.z-dn.net/?f=%5BOH%5E-%5D%3D1.12%5Ctimes%2010%5E%7B-13%7DM)
The concentration is,
If the humidity of the room is low, the water that contacts the air directly could evaporate and takes some energy from the bulk thus decreasing its temperature steadily. This allows the water to have a lower temperature.
1 is The first one
<span>2 is the third one
3 is the second one
4 is the 4th one</span>
