Answer:
the water underwent a physical change. This is because the water simply changed states, and could become liquid again, but it will remain H20 throughout the time
Answer:
First option
Explanation:
Students 1 and 2 have precise measures yet is is not accurate since they measure around 5.
Answer:
cool the tractor water system
Answer:
9.36
Explanation:
Sodium formate is the conjugate base of formic acid.
Also,

for sodium formate is 
Given that:
of formic acid = 
And, 
So,


Concentration = 0.35 M
HCOONa ⇒ Na⁺ + HCOO⁻
Consider the ICE take for the formate ion as:
HCOO⁻ + H₂O ⇄ HCOOH + OH⁻
At t=0 0.35 - -
At t =equilibrium (0.35-x) x x
The expression for dissociation constant of sodium formate is:
![K_{b}=\frac {[OH^-][HCOOH]}{[HCOO^-]}](https://tex.z-dn.net/?f=K_%7Bb%7D%3D%5Cfrac%20%7B%5BOH%5E-%5D%5BHCOOH%5D%7D%7B%5BHCOO%5E-%5D%7D)

Solving for x, we get:
x = 0.44×10⁻⁵ M
pOH = -log[OH⁻] = -log(0.44×10⁻⁵) = 4.64
pH + pOH = 14
So,
<u>pH = 14 - 4.64 = 9.36</u>
Answer:
Therefore, The indicator that is best fit for the given titration is Bromocresol Green Color change from pH between 4.0 to 5.6
Bromocresol green, color change from pH = 4.0 to 5.6
Explanation:
The equation for the reaction is :

concentration of
= 10%
10 g of
in 100 ml solution
molar mass = 45.08 g/mol
number of moles = 10 / 45.08
= 0.222 mol
Molarity of 
= 2.22 M
number of moles of
in 20 mL can be determined as:

Concentration of 
= 2.22 M
Similarly, The pKa Value of
is given as 10.75
pKb value will be: 14 - pKa
= 14 - 10.75
= 3.25
the pH value at equivalence point is,
![pH= \frac{1}{2}pKa - \frac{1}{2}pKb-\frac{1}{2}log[C]](https://tex.z-dn.net/?f=pH%3D%20%5Cfrac%7B1%7D%7B2%7DpKa%20-%20%5Cfrac%7B1%7D%7B2%7DpKb-%5Cfrac%7B1%7D%7B2%7Dlog%5BC%5D)
![pH = \frac{14}{2}-\frac{3.25}{2}-\frac{1}{2}log [2.22]](https://tex.z-dn.net/?f=pH%20%3D%20%5Cfrac%7B14%7D%7B2%7D-%5Cfrac%7B3.25%7D%7B2%7D-%5Cfrac%7B1%7D%7B2%7Dlog%20%5B2.22%5D)

Therefore, The indicator that is best fit for the given titration is Bromocresol Green Color change from pH between 4.0 to 5.6