Answer:
Condenser
Explanation:
Condenser is highly efficient when dealing with the vapors of the product are need to be liquified. It is mostly automated and regularly condenses the incoming vapors into liquid. It is very easy to use. All we have to do it to attach incoming and outgoing flow pipes and constantly monitor the flow of cold water through the condenser. It is made up of special kind of PYREX glass so that it won't break when dealing with steam.
From the ideal gas equation,

where n is number of moles, R is Universal gas constant, P is pressure, V is volume, and T is temperature of the gas.
The pressure and volume are inversely proportional to each other at constant temperature and number of moles.
Hence, on decreasing the pressure, the volume will increase.
As the hiker reaches a height of a mountain, the pressure would decrease which results in the reestablishment of equilibrium between gas molecules thus resulting in pushing of bag outwards.
Hence, the bag will expand as the hiker reaches the top of the mountain.
You can determine the hazards of these chemicals by looking at their material data safety sheets (MSDS).
1. 0.1 M Ag⁺: Silver compounds are absorbed by skin causing bluish pigmentation. Thus, it <em>causes </em><span><em>staining on skin</em>.</span> Also, liquid <em>vapor may be irritating</em> to skin and also <em>moderately toxic when ingested</em>.
2. 0.1 M Ba²⁺: This is <em>mildly toxic when ingested</em> causing stomach irritation, muscle weakness, swelling of organs like brain, liver, kidney and heart.
3. 0.1 M Fe³⁺:Iron is <em>corrosive, has irritating vapor especially to the eyes, and toxic if ingested</em>.
4. 6 M HCl: This is a concentrated strong acid, so it is <em>corrosive, has irritating vapors, flammable and toxic when ingested</em>.
5. 6 M H₂SO₄: This is also a concentrated strong acid. Moreover, it is a strong oxidizing agent. So, its hazards include: <span><em>corrosive, has irritating vapors, toxic when ingested and causes staining on skin</em>.
</span>6. 6 M HNO₃: This is a concentrated strong acid, so it is <em>corrosive, has irritating vapors, flammable and toxic when ingested</em>.
7. 7.5 M NH₃: This is a weak base. It is characterized for its pungent odor. This is <em>corrosive, has irritating vapors, toxic if ingested, and flammable</em>.
Number of moles of NaOH = V(NaOH) * M(NaOH)= 0.150 L * 0.1 moles/L = 0.015 moles
Number of moles of formic acid, HCOOH = V(HCOOH) * M(HCOOH) = 0.200 L * 0.1 moles/L = 0.020 moles
Here, the limiting reagent is NaOH
The reaction is represented as:
HCOOH + NaOH ↔HCOONa + H2O
Moles of HCOONa formed = Moles of the limiting reagent, NaOH = 0.015 moles
Moles of HCOOH remaining = 0.020-0.015 = 0.005 moles
Total final volume is given as 1 L
Therefore: [HCOOH] = 0.005 moles/1 L = 0.005 M
[HCOONa] = 0.015/1 = 0.015 M
pKa of HCOOH = 3.74
As per Henderson-Hasselbalch equation
pH = pka + log[HCOONa]/[HCOOH] = 3.74+log[0.015/0.005] = 4.22
Therefore, pH of the final solution = 4.22