Answer: The correct answer is Heterogeneous mixture
Explanation:
Heterogeneous mixture are those mixture in which:
- Substance is distributed in non uniform manner.
- Two distinct layers are formed
Thus when water and dirt are mixed together it results in the formation of a heterogeneous mixture and after sometimes two different layers will be observed.
Hence, in the bottle there is a heterogeneous mixture of water and dirt.
Any buffer exists in this equilibrium
HA <=>

In a buffer, there is a large reservoir of both the undissociated acid (HA) and its conjugate base (

)
When a strong acid is added, it reacts with the large reservoir of the conjugate base (

) forming a salt and water. Since this large reservoir of the conjugate base is used, the ph does not alter drastically, but instead resist the pH change.
Answer:
The volume of HCl to be added to completely react with the ammonia is 0.032 L or 32mL
Explanation:
Using the formula
Ca Va = Cb Vb
Cb = 0.32 M
Vb = 50 mL = 50/1000 = 0.050L
Ca = 0.5 M
Va =?
Substituting for Va in the equation, we obtain:
Va = Cb Vb / Ca
Va = 0.32 * 0.05 / 0.5
Va = 0.016 / 0.5
Va = 0.032 L
The volume of HCl to be added to completely react with the ammonia is 0.032 L or 32mL