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erastovalidia [21]

1 year ago

10

Given that ethylene has a λmax of 175nm, butadiene has a λmax of 220nm, and 2-methyl-1,3-butadiene has a λmax or 215nm, what is

the λmax of 2,3,4-trimethylhexatriene?

1 answer:

Vika [28.1K]1 year ago

5 0

The λmax of 2,3,4-trimethylhexatriene is 280 nm.

Ethylene has a λmax of 175nm.

Butadiene has a λmax of 220nm.

2-methyl-1,3-butadiene has a λmax or 215nm.

1,3,5-hexatriene has a λmax of 258nm.

Woodward's rules, sometimes known as Woodward-Fieser rules (after Louis Fieser) and named after Robert Burns Woodward, are a number of sets of empirically developed principles that aim to forecast the wavelength of the absorption maximum (max) in an ultraviolet-visible spectrum of a certain molecule.

By using the Woodward Fieser rule,

R- (Alkyl Group) .... +5 nm = 5 × 2 = 10

RO- (Alkoxy Group) .. +6 = 6 × 2 = 12

Adding 22nm to the λmax of 1,3,5-hexatriene as it has 2 alkyl groups and 2 alkoxy groups to form 2,3,4-trimethylhexatriene.

The λmax of 2,3,4-trimethylhexatriene is 280 nm.

Learn more about Woodward-Fieser here:

brainly.com/question/16982345

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During a rockslide, a 670 kg rock slides from rest down a hillside that is 740 m along the slope and 240 m high. The coefficient

ElenaW [278]

a) $1.58\cdot 10^6 J$

b) $1.15\cdot 10^6 J$

c) $0.43\cdot 10^6 J$

d) 35.8 m/s

Explanation:

a)

The gravitational potential energy of an object is the energy possessed by the object due to its location with respect to the ground.

It is given by:

$U=mgh$

where

m is the mass of the object

g is the acceleration due to gravity

h is the height of the object, relative to a reference level

Here, the reference level is taken at the bottom of the hill (where the potential energy is zero).

So, we have:

m = 670 kg is the mass of the rock

$g=9.8 m/s^2$

h = 240 m is the initial height of the rock

So, the potential energy of the rock just before the slide is

$U=(670)(9.8)(240)=1.58\cdot 10^6 J$

b)

The energy transferred to thermal energy during the slide is equal to the work done by friction, which is:

$W=F_f d$

where

$F_f$ is the force of friction

d = 740 m is the displacement of the rock along the ramp

The force of friction is given by:

$F_f=-\mu mg cos \theta$

where

$\mu=0.25$ is the coefficient of friction

m = 670 kg is the mass of the rock

$\theta$ is the angle of the ramp

Since we know the lenght of the ramp (d = 740 m) and the height (h = 240 m), we can find the angle:

$\theta=sin^{-1}(\frac{h}{d})=sin^{-1}(\frac{240}{740})=18.9^{\circ}$

Therefore, the work done by friction is:

$W=-\mu m g cos \theta d =-(0.25)(670)(9.8)(cos 18.9^{\circ})(740)=-1.15\cdot 10^6 J$

So, the energy transferred to thermal energy is $1.15\cdot 10^6 J$ .

c)

According to the law of conservation of energy, the kinetic energy of the rock as it reaches the bottom of the hill will be equal to the initial potential energy (at the top) minus the energy transformed into thermal energy.

Therefore, we have:

$K_f = U_i -E_t$

where here we have:

$U_i=1.58\cdot 10^6 J$ is the potential energy of the rock at the top of the hill

$E_t=1.15\cdot 10^6 J$ is the energy converted into thermal energy

Substituting, we find

$K_f=1.58\cdot 10^6-1.15\cdot 10^6=0.43\cdot 10^6 J$

So, this is the kinetic energy of the rock at the bottom of the hill.

d)

The kinetic energy of the rock at the bottom of the hill can be rewritten as

$K_f=\frac{1}{2}mv^2$

where

m is the mass of the rock

v is its final speed

In this problem, we have:

$K_f=0.43\cdot 10^6 J$ is the final kinetic energy of the hill

m = 670 kg is the mass of the rock

Therefore, the final speed of the rock is:

$v=\sqrt{\frac{2K_f}{m}}=\sqrt{\frac{2(0.43\cdot 10^6)}{670}}=35.8 m/s$

7 0

3 years ago

Krichoffs law of current questions

postnew [5]

Answer:

Explanation:

Kirchhoff's Current Law, often shortened to KCL, states that “The algebraic sum of all currents entering and exiting a node must equal zero.

#I AM ILLITERATE

6 0

2 years ago

Compare and contrast the molecular structure of cleaning bleach and carbon monoxide

dangina [55]

For a very long time, the only real laundry bleach on the market was chlorine bleach, popularized by industry leaders, such as Clorox. Bleach is not only used for stain removal in laundry, but to clean and sterilize objects and surfaces. Chlorine bleach is not good for every fabric and has a very harsh smell, so oxygen bleaches were developed that clean as well as chlorine bleaches in most applications, but are safer on fabrics and are less harsh. Both are effective, but one may be preferable over the other depending on the application.Chlorine Bleach

Chlorine beach is sodium hypochlorite, diluted with water to around a five percent concentration. Manufacturers make it by heating lye (sodium hydroxide) or quicklime (calcium hydroxide) and allowing chlorine gas to bubble up through it. They then add water to the right concentration. Chlorine bleach is highly caustic. It will eat away fabric and skin if left on for an extended period, especially at full strength and take away color. Chlorine bleach is typically diluted even further when used for stain removal or cleaning. It is an unstable product that begins to lose its effectiveness after manufacturing and becomes ineffective over time, and must be stored in a cool, dark place in a plastic container.

Oxygen Bleach

Oxygen bleach is hydrogen peroxide with some sodium and sometimes carbon added to it to form a compound that releases the hydrogen peroxide when added to water. Oxygen leach is a more highly concentrated product than chlorine bleach. Many times, it is found in powdered form, which is then added to water to activate it. Oxygen bleach is known as “color-safe” or “all fabric” bleach, since it does not degrade most fabric or strip most color if used correctly, though you must still test colorfastness before using. It is very stable and can be kept for over a year with no loss of effectiveness. However, it should never be stored in metal or organic containers.

Similarities

Both bleaches work by oxidizing stains and microbes, allowing them to be broken up and lifted away from fabrics and surfaces. Both have excellent anti-microbial qualities that make them good for disinfecting laundry and surfaces, though chlorine bleach has an edge in effectiveness. Neither is effective in cold water, and both require garments be rinsed well after use.

Benefits

Chlorine bleach does not differentiate between color molecules and stains or microbes; it lifts colors away using oxidation as well. Even in low concentrations, it eats away at fabric, so over time, the regular use of bleach will deteriorate garments and fade their color. Chlorine bleach is toxic to aquatic life if released straight into surface water, as in stormdrain runoff from outdoor cleaning projects. It is also harmful to the essential bacteria in septic tanks if used in anything but very small quantities. It works best in hot water, but is also effective in warm water. It cannot be used with other cleaners such as ammonia, as contact can released deadly chlorine gas. It is less expensive to use than oxygen bleach.

Considerations

Oxygen bleach is safe to use on nearly any fabric and to add to laundry loads for extended periods with no damage to clothing. Oxygen bleach turns to water and oxygen when broken down, so it has no negative impact to the environment and is safe for septic systems. It is best if used in the same step as laundry detergent, which makes it even more effective, but combining steps also saves time. It only works well in hot water, but additives can make it effective in warm water.

4 0

3 years ago

A diver is swimming underneath an oil slick with a thickness of 200 nm and an index of refraction of 1.50. A white light shines

Tcecarenko [31]

Answer:

Explanation:

thickness of oil t = 200 nm

index of refraction μ = 1.5

For transmitted light :---

path difference = 2μ t

For constructive interference

path difference = n λ , λ is wavelength of light

2μ t = n λ

λ = 2μ t / n

For longest λ , n = 1

λ = 2μ t

= 2 x 1.5 x 200 nm

= 600 nm

Wavelength in water

= 600 / refractive index of water

= 600 / 1.33

= 451.1 nm Ans

4 0

3 years ago

The minimum energy needed to eject an electron from a sodium atom is 4.41 x 10-19 j. what is the maximum wavelength of light, in

Minchanka [31]

The energy of an electron as it is ejected from the atom can be calculated from the product of the Planck's constant and the frequency of the light energy. We can calculate the wavelength from the frequency we can calculate. We do as follows:

E = hv
4.41 x 10-19 = 6.62607004 × 10<span>-34 (v)
v = 6.66x10^14 /s

wavelength = speed of light / frequency
</span>
wavelength = 3x10^8 / 6.66x10^14
wavelength = 4.51x10^-7 m = 450.75 nm

5 0

3 years ago