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3 years ago

If an ultraviolet photon has a wavelength of 77.8 nm calculate the energy of one mole ultraviolet photon.

Chemistry

1 answer:

DerKrebs [107]3 years ago

7 0

Answer:

Explanation:

E = (hc)/(λ)

E = (6.624x10^(-27))Js x ((3×10^8)ms^(-1)) /

(77.8x10^(-9)m)

E = 2.55 x 10^(-11) J

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Eva pumps up her bicycle tire until it has a gauge pressure of 413 kilopascals. If the surrounding air is at standard pressure,

KIM [24]

The tire pressure is the sum of gauge pressure and the standard pressure of atmospheric pressure

We know that the standard air pressure of surrounding = 101.325 kPa

The given gauge pressure = 413 kPascal

So the tire pressure = 101.325 kPa + 413 = 514.325 K Pa

We can also convert the given pascals to atmosphere or Torr or mmHg or bar

5 0

3 years ago

Read 2 more answers

Consider the balanced equation below.

Alexus [3.1K]

Answer : The mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2 and

the mole ratios of Hydrazine to water is 1 : 4.

Explanation :

The balanced chemical equation is,

$N_{2}H_{4}+2H_{2}O_{2}\rightarrow N_{2}+4H_{2}O$

According to the given reaction,

1 mole of Hydrazine react with the 2 moles of Hydrogen peroxide.

Therefore, the mole ratios of Hydrazine to Hydrogen peroxide is 1 : 2

And in case of Hydrazine and water,

1 mole of Hydrazine gives 4 moles of water.

Therefore, the mole ratios of Hydrazine to water is 1 : 4

5 0

3 years ago

Read 2 more answers

A piece of unknown metal with mass 68.6 g is heated to an initial temperature of 100 °C and dropped into 42 g of water (with an

professor190 [17]

Answer:

1.717 J/g °C ( third option)

Explanation:

A piece of the unknown metal dropped into water this means that Q of metal is equal to Q of the water. We write this equality as follows:

Step 1: writing the formulas:

Q = mc∆T

⇒ -Q(metal) = Q(water) Because :Metal dropped into water this means that Q of metal is equal to Q of the water.

We can write the formula different :

Mass of metal * (cmetal)(ΔT) = Mass of water *(cwater) (ΔT)

⇒ Here c is the specific heat and depends on material and phase

For this case :

mass of the metal = 68.6g

mass of the water = 42g

Specific heat of the metal = TO BE DETERMINED

Specific heat of the water = 4.184J/g °C

Initial temperature of the metal = 100 °C ⇒ Change of temperature: 52.1 - 100

Initial temperature of the water = 20°C ⇒ Change of temperature: 52.1 - 20

Step 2: Calculating specific heat of the metal

-(Mass of metal) * (cmetal)*(ΔT)) = (Mass of water) *(cwater)*(ΔT)

-68.6g (cmetal)(52.1 - 100) = 42g (4.184j/g °C) (52.1 - 20)

-68.6g *cmetal * (-47.9) = 42g (4.184j/g °C) *(32.1)

3285.94 * cmetal = 5640.87

cmetal = 5640.87 / 3285.94 = 1,71667 J/g °C

cMetal = 1.717 J/g °C

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3 years ago

The following pieces of evidence were found at separate explosion sites. For each item, indicate whether the explosion was more

tangare [24]

Explanation:

The major difference between low and high explosives is the rate of detonation. Low explosives detonate very slowly (less than 1,000 meters per second), whereas high explosives detonate very quickly (from 1,000 to 8,500 meters per second).

High explosives among the given list are Lead azide residues, Ammonium nitrate residues, and Scraps of primacord. Whereas Nitrocellulose residues and, Potassium chlorate residues are low explosives.

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3 years ago

In the lewis structure of ch3oh, how many lone pairs of electrons are there? in the lewis structure of ch3oh, how many lone pair

Lunna [17]

The structure of Methanol (CH₃OH) is shown below. This structure contains 2 lone pair of electrons on oxygen (highlighted red). Electronic configuration of oxygen is,

Oxygen = 8 = 1s², 2s², 2px², 2py¹, 2pz¹

There are six electrons in valence shell of oxygen, among these six electrons two electrons are unpaired and involved in forming covalent bond with hydrogen and carbon, while remaining 4 electrons in pair (i.e. 2s², 2px²) exists as lone pairs.

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4 years ago