Hello!
To determine [H₃O⁺], we need to apply the Henderson-Hasselback equation, since this is a case of an acid and its conjugate base:
![pH=pKa+log( \frac{[A^{-}] }{[HA]} )](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%28%20%5Cfrac%7B%5BA%5E%7B-%7D%5D%20%7D%7B%5BHA%5D%7D%20%29)

Now, we use the definition of pH and clear [H₃O⁺] from there:
![pH=-log[H_3O^{+}]](https://tex.z-dn.net/?f=pH%3D-log%5BH_3O%5E%7B%2B%7D%5D%20)
![[H_3O^{+}] = 10^{-pH} =10^{-3,84}=0,00014 M](https://tex.z-dn.net/?f=%20%5BH_3O%5E%7B%2B%7D%5D%20%3D%2010%5E%7B-pH%7D%20%3D10%5E%7B-3%2C84%7D%3D0%2C00014%20M)
So, the [H₃O⁺] concentration is
0,00014 M
Have a nice day!
ΔH(reaction) = ΔH(formation of products) - ΔH(formation of reactants)
ΔH(reaction) = ( 1*ΔH(Pb(s)) + 1*ΔH(CO2(g)) ) - ( 1*ΔH(PbO(s)) + 1*ΔH(CO(g)) )
ΔH(reaction) = ( 0 + -393.5 ) - ( ΔH(PbO(s)) + -110.5 )
ΔH(reaction) = -283 - ΔH(PbO(s))
-131.4 = -283 -ΔH(PbO(s))
ΔH(PbO(s)) = -151.6 kJ
So, the best answer is A.
I know this isn't the answer but here's an English translation
<span>The saturated vapor pressure of pure water at 20 ° C is 18 mmHg. If at the same temperature as much as 120 grams of x-substance dissolved in 990 grams of water, the vapor pressure of the solution becomes 17.37 mmHg, calculate the relative molecular mass of the substance x?</span>
Answer:
See explanation
Explanation:
Sr(s) + 2HCl(aq) -----> SrCl2(aq) + H2(g)
Ionically;
Sr(s) + 2Cl^-(aq) ----> SrCl2(aq)
If we look at the reaction above, strontium atom was dissolved in hydrochloric acid. The strontium atom is now oxidized by the acid to give Sr^2+ ion according to the equation shown above.
Explanation: Saponification reaction is a reaction in which hydrolysis of fats takes place under basic conditions giving glycerol and a salt of corresponding fatty acid.
We are given a Fatty acid called as Trimyristin.
Its reaction with KOH leads to the formation of soap and is given by the equation:


The condensed structural formula for the equation is given in the image attached.