pH scale is used to measure the acidity or alkalinity on a scale of 0-14 where 0-6.9 is the acidic region , 7.1-14 is the basic region and 7 is for the neutral substance. We can calculate the concentration of proton from pH.
![pH=-log[H^+]](https://tex.z-dn.net/?f=pH%3D-log%5BH%5E%2B%5D)
where ![[H^+]](https://tex.z-dn.net/?f=%5BH%5E%2B%5D)
is the concentration of proton
As per the question ,the pH of coffee is 5.6 and we need to find the concentration of proton so putting the values in the above equation, we get
![5.6=-log[H^+]](https://tex.z-dn.net/?f=5.6%3D-log%5BH%5E%2B%5D)
![-5.6=log[H^+]](https://tex.z-dn.net/?f=-5.6%3Dlog%5BH%5E%2B%5D)
![antilog(-5.6)= [H^+]](https://tex.z-dn.net/?f=antilog%28-5.6%29%3D%20%5BH%5E%2B%5D)
![[H^+]= 2.511\times10^-^6 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3D%202.511%5Ctimes10%5E-%5E6%20M)
Pretty sure A is the correct answer
Answer:
1.Most metal oxides are insoluble in water but some of these (e.g. Na2O.
Explanation:
2.: (i) A hissing sound is observed.
1.ii) The mixture starts boiling and lime water is obtained.
3Mg + N₂ → Mg₃N₂
n(Mg) = 12,2g÷24,4g/mol = 0,5mol - limiting reagente.
n(N₂) = 5,16g÷28g/mol = 0,18mol
n(Mg₃N₂):n(Mg) = 1:3, n(Mg₃N₂) = 0,166mol
m(Mg₃N₂) = 0,166mol·101,2g/mol = 16,8g.
%(N)= 2·Ar(N)÷Mr(Mg₃N₂) = 2·14÷101,2 = 27,66% = 0,2766
%(Mg) = 3·Ar(Mg)÷Mr(Mg₃N₂) = 3·24,4÷101,2 = 72,34%
or 100% - 27,66% = 72,34%.
