Equilibrium expression is ![Keq = \frac{[H3O+][HCO3^-]}{[H2CO3]}\\](https://tex.z-dn.net/?f=Keq%20%3D%20%5Cfrac%7B%5BH3O%2B%5D%5BHCO3%5E-%5D%7D%7B%5BH2CO3%5D%7D%5C%5C)
<u>Explanation:</u>
Equilibrium expression is denoted by Keq.
Keq is the equilibrium constant that is defined as the ratio of concentration of products to the concentration of reactants each raised to the power its stoichiometric coefficients.
Example -
aA + bB = cC + dD
So, Keq = conc of product/ conc of reactant
![Keq = \frac{[C]^c [D]^d}{[A]^a [B]^b}](https://tex.z-dn.net/?f=Keq%20%3D%20%5Cfrac%7B%5BC%5D%5Ec%20%5BD%5D%5Ed%7D%7B%5BA%5D%5Ea%20%5BB%5D%5Eb%7D)
So from the equation, H₂CO₃+H₂O = H₃O+HCO₃⁻¹
![Keq = \frac{[H3O^+]^1 [HCO3^-]^1}{[H2CO3]^1 [H2O]^1}](https://tex.z-dn.net/?f=Keq%20%3D%20%5Cfrac%7B%5BH3O%5E%2B%5D%5E1%20%5BHCO3%5E-%5D%5E1%7D%7B%5BH2CO3%5D%5E1%20%5BH2O%5D%5E1%7D)
The concentration of pure solid and liquid is considered as 1. Therefore, concentration of H2O is 1.
Thus,
![Keq = \frac{[H3O+][HCO3^-]}{[H2CO3]}\\](https://tex.z-dn.net/?f=Keq%20%3D%20%5Cfrac%7B%5BH3O%2B%5D%5BHCO3%5E-%5D%7D%7B%5BH2CO3%5D%7D%5C%5C)
Therefore, Equilibrium expression is ![Keq = \frac{[H3O+][HCO3^-]}{[H2CO3]}\\](https://tex.z-dn.net/?f=Keq%20%3D%20%5Cfrac%7B%5BH3O%2B%5D%5BHCO3%5E-%5D%7D%7B%5BH2CO3%5D%7D%5C%5C)
<u>Answer:</u> The final temperature of the coffee is 43.9°C
<u>Explanation:</u>
To calculate the final temperature, we use the equation:

where,
q = heat released = 
m = mass of water = 10.0 grams
C = specific heat capacity of water = 4.184 J/g°C
= final temperature = ?
= initial temperature = 20°C
Putting values in above equation, we get:

Hence, the final temperature of the coffee is 43.9°C
The formula for molality---> m = moles solute/ Kg of solvent
the solute here is NH₃ because it's the one with less amount. which makes water the solvent.
1) let's convert the grams of NH₃ to moles using the molar mass
molar mass of NH₃= 14.0 + (3 x 1.01)= 17.03 g/ mol
15.0 g (1 mol/ 17.03 g)= 0.881 mol NH₃
2) let's convert the grams of water into kilograms (just divide by 1000)
250.0 g= 0.2500 kg
3) let's plug in the values into the molality formula
molality= mol/ Kg---> 0.881 mol/ 0.2500 kg= 3.52 m
The elements of the "Noble" gases group is nonreactive. The reason for this is that noble gases are always or most of the time at room temperature.<span />