Answer:
a) pH = 4.68 (more effective)
b) pH =4.44.
Explanation:
The pH of buffer solution is obtained by Henderson Hassalbalch's equation.
The equation is:
![pH =pKa +log\frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pH%20%3DpKa%20%2Blog%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
a) pKa of acetic acid = 4.74
[salt] = [CH₃COONa] = 1.4 M
[acid] = [CH₃COOH] = 1.6 M
This is more effective as there is very less difference in the concentration of salt and acid.
b) pKa of acetic acid = 4.74
[salt] = [CH₃COONa] = 0.1 M
[acid] = [CH₃COOH] = 0.2 M
A solution of K2SO4 and KCl is added to a solution of Ba(NO3)2. BaS0₄ (s) will precipitate out of this combined solution.
Molecular equation
K2SO4(aq) + Ba(NO3)2(aq) → BaSO4(s) + 2 KNO3(aq)?
This equation represents a double displacement (replacement) reaction, also called a metathesis reaction, in which the reactant ions exchange places to form new products. The general equation is:
A-B + C-D → A-D + C-B;
where A and C are cations, and B and D are anions.
Complete ionic equation: Includes all ions and the precipitate.
2K^+(aq) + SO4^2-(aq) + Ba^2+(aq) + 2[NO3]^-(aq) → 2K^+(aq) + 2[NO3]^- + BaSO4(s)
In an aqueous solution, precipitation is the process of transforming a dissolved substance into an insoluble solid from a super-saturated solution.
The solid formed is called the precipitate. In case of an inorganic chemical reaction leading to precipitation, the chemical reagent causing the solid to form is called the precipitant.
Learn more about precipitation here : brainly.com/question/1783904
#SPJ4
Answer:
The bottom layers of the rock could have formed before life occurred.
Explanation:
The bottom layers of the rock could have formed before life occurred because there is no fossil is present. If there is life at that time so the fossils are present at the bottom layer so the absence indicates that is no life present at that time. The bottom layer is older than the upper layer so that's why fossils of bacteria are found in the upper layer of the rock.
Answer:
C. Because bacterial fossils are found only in the upper layers, scientists can conclude that these bacteria evolved towards the end of Precambrian time.
There’s two different types of answers for this question so I just put both of them. Hope it helps : )
Answer:
Specific gravity of the sample = 8.947
Explanation:
Specific gravity of a substance is defined as the density of that substance divided by the density of water.
Density of water = 1000g/l
Density of substance = mass/volume
= 85/9.5 x 10^-3
= 8947.37 g/l
SG = 8947.37/1000
= 8.947
