The answer is without access to energy
I believe the answer is Exothermic
Solution :
For the reaction :
we have
![$Ka = \frac{[\text{Tris}^- \times H_3O]}{\text{Tris}^+}$](https://tex.z-dn.net/?f=%24Ka%20%3D%20%5Cfrac%7B%5B%5Ctext%7BTris%7D%5E-%20%5Ctimes%20H_3O%5D%7D%7B%5Ctext%7BTris%7D%5E%2B%7D%24)
Clearing 
, we have 
So to reach 
, one must have the 
concentration of the :
![$\text{[OH}^-]=10^{-pOH} = 6.31 \times 10^{-7} \text{ moles of base}$](https://tex.z-dn.net/?f=%24%5Ctext%7B%5BOH%7D%5E-%5D%3D10%5E%7B-pOH%7D%20%3D%206.31%20%5Ctimes%2010%5E%7B-7%7D%20%5Ctext%7B%20moles%20of%20base%7D%24)
So we can add enough of 1 M NaOH in order to neutralize the acid that is calculated above and also adding the calculated base.
Volume NaOH 
Tris mass 
Now to prepare the said solution we must mix:
gauge to 1000 mL with water.
Surface tension is the result of water molecules pulling inward with a strong attractive force.
The attractive force brings the molecules on the surface of the water close together.
The attractive force causes the surface of the water to be drawn toward the water molecules beneath the surface. <span>
Since there are no water molecules above the surface, there are uneven forces. This causes surface tension, allowing the coin to float on the water’s surface.</span>
Answer:
2.33g of iron (iii) chloride
50.0 mL of 5.00 M of sodium phosphate
FeCl3 + Na3PO4 > Fe(PO4) + 3NaCl
mol = conc × vol = 0.5 × 50/1000 = 0.025 mol Na3PO4
from the equation:
1 mol of Na3PO4 reacts with 1 mol FeCl3 = 3 mol of NaCl
0.025 mol = x
x = 0.0025 × 3 = 0.075 mol NaCl
mass = 0.075 g × 59 g/mol = 4.425 g NaCl
i guessed all of this so i dont know i it is correct
