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2 years ago

Soap is a very interesting chemical. We even discussed it on the discussion board. How does it work, exactly?

Engineering

1 answer:

soldi70 [24.7K]2 years ago

4 0

Answer:

Saponification is a process in which soap is formed from mixtures of sodium or potassium salts of fatty acids. These fatty acids are reacted high temperature of At 80°C-100°C with alkali to extract salt. These alkali can be sodium hydroxide or potassium hydroxide.

Soap has both polar (ionic) and non polar molecules due to which it has characteristics of both hydrophilic substance (having tendency to mix with water) and hydrophobic substance (have tendency to mix with oils) and due to this nature it can act as an emulsifier.

An emulsifier has tendency to diffuse one liquid into another liquid which is incapable of mixing with homogeneous liquid like water.

Cleansing action takes place due to presence of ionic and non-polar properties at same time, in combination with solubility principles. The ionic end of soap molecule is the salt end. It is hydrophilic (water soluble) in nature. The non-polar end cotains long hydrocarbon chains and is hydrophobic (water repellent).

When immiscible liquids like grease or oil mixed with soap water, non polar end (hydrophobic end) absorbs the dirt which means the soap will form the micelles and trap the dirt in it. As micelles is soluble in water it will remove the dirt with it.

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The rectangular frame is composed of four perimeter two-force members and two cables AC and BD which are incapable of supporting

Rama09 [41]

Answer:

Your question is lacking some information attached is the missing part and the solution

A) AB = AD = BD = 0, BC = LC

AC = $\frac{5L}{3}T, CD = \frac{4L}{3} C$

B) AB = AD = BC = BD = 0

AC = $\frac{5L}{3} T, CD = \frac{4L}{3} C$

Explanation:

A) Forces in all members due to the load L in position A

assuming that BD goes slack from an inspection of Joint B

AB = 0 and BC = LC from Joint D, AD = 0 and CD = 4L/3 C

B) steps to arrive to the answer is attached below

AB = AD = BC = BD = 0

AC = $\frac{5L}{3} T, CD = \frac{4L}{3}C$

7 0

2 years ago

Consider insulation on a circular pipe For the same thickness and type of insulation, the thermal resistance of the insulation i

leonid [27]

Answer:

b). The same for all pipes independent of the diameter

Explanation:

We know,

$R_{conduction}=\frac{ln(\frac{r_{2}}{r_{1}})}{2\pi LK}$

$R_{convection}=\frac{1}{h(2\pi r_{2}L)}$

From the above formulas we can conclude that the thermal resistance of a substance mainly depends upon heat transfer coefficient,whereas radius has negligible effects on heat transfer coefficient.

We also know,

Factors on which thermal resistance of insulation depends are :

1. Thickness of the insulation

2. Thermal conductivity of the insulating material.

Therefore from above observation we can conclude that the thermal resistance of the insulation is same for all pipes independent of diameter.

5 0

2 years ago

A railcar with an overall mass of 78,000 kg traveling with a speed vi is approaching a barrier equipped with a bumper consisting

sergij07 [2.7K]

Answer:

v₀ = 2,562 m / s = 9.2 km/h

Explanation:

To solve this problem let's use Newton's second law

F = m a = m dv / dt = m dv / dx dx / dt = m dv / dx v

F dx = m v dv

We replace and integrate

-β ∫ x³ dx = m ∫ v dv

β x⁴/ 4 = m v² / 2

We evaluate between the lower (initial) integration limits v = v₀, x = 0 and upper limit v = 0 x = x_max

-β (0- x_max⁴) / 4 = ½ m (v₀²2 - 0)

x_max⁴ = 2 m /β v₀²

Let's look for the speed that the train can have for maximum compression

x_max = 20 cm = 0.20 m

v₀ =√(β/2m) x_max²

Let's calculate

v₀ = √(640 106/2 7.8 104) 0.20²

v₀ = 64.05 0.04

v₀ = 2,562 m / s

v₀ = 2,562 m / s (1lm / 1000m) (3600s / 1h)

v₀ = 9.2 km / h

5 0

2 years ago

If water molecules pass through a membrane with a steady state flux of 220 mole/(m2 day), how long will it take, in hours, for 0

goblinko [34]

Answer:

0.0386 hr

Explanation:

Area = 565 cm^2 = 0.0565 m^2 (1 cm^2 = 0.0001 m^2)

flux state rate = 220 mole/m^2-day

There are 24 hrs in a day, therefore rate in hrs will be

220/24 = 9.17 mole/m^2-hr

mass of water = 0.4 kg

molar mass of water = (1 x 2) + 16 = 18 kg/mole

therefore,

mole of water = mass of water/molar mass of water

mole of water = 0.4/18 = 0.02 mole

mole flux = mole/area = 0.02/0.0565 = 0.354 mol/m^2

time that will be taken will be for water to pass = mole flux/mole flux rate

time = 0.354/9.17 = 0.0386 hr

7 0

2 years ago

An overpass is being built over the PVI of an existing equal-tangent sag curve. The sag curve has a 70 mi/h design speed and G1=

vivado [14]

Answer: Resultant elevation will be 30.98 ft

8 0

2 years ago