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3 years ago

What is the amount of heat released when 25g of water cools 12.5 degrees C ?

1 answer:

4 0

Water can't cool at a single temperature. It must start at a higher temperature, and drop to a lower temperature in order to cool. Unless we know the other temperature, there is no way to calculate the amount of thermal energy released.

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Calculate the wavelength, in nanometers, of the spectral line produced when an electron in a hydrogen atom undergoes the transit

Lapatulllka [165]

Answer: The wavelength of spectral line is 656 nm

Explanation:

To calculate the wavelength of light, we use Rydberg's Equation:

$\frac{1}{\lambda}=R_H\left(\frac{1}{n_f^2}-\frac{1}{n_i^2} \right )$

Where,

$\lambda$ = Wavelength of radiation

$R_H$ = Rydberg's Constant = $1.097\times 10^7m^{-1}$

$n_f$ = Final energy level = 2

$n_i$ = Initial energy level = 3

Putting the values in above equation, we get:

$\frac{1}{\lambda }=1.097\times 10^7m^{-1}\left(\frac{1}{2^2}-\frac{1}{3^2} \right )\\\\\lambda =\frac{1}{1.524\times 10^6m^{-1}}=6.56\times 10^{-7}m$

Converting this into nanometers, we use the conversion factor:

$1m=10^9nm$

So, $6.56\times 10^{-7}m\times (\frac{10^9nm}{1m})=656nm$

Hence, the wavelength of spectral line is 656 nm

6 0

3 years ago

A chemical reaction is the process by which a ___ takes place

Verizon [17]

A chemical reaction is the process by which a CHANGE takes place (?)

4 0

3 years ago

Read 2 more answers

Which three words best describe the composition of the inner planets? solid, smooth, giant rocky, solid, dense giant, dense, gas

Lapatulllka [165]

Answer:

solid, rocky, dense

Explanation:

3 0

4 years ago

Read 2 more answers

Convert 150.0 g to mg.

tatyana61 [14]

There are 1000 milligrams in a gram, so you can find the answer through multiplication: 150 • 1000

The answer is 150,000

6 0

3 years ago

Grignard reactions are usually performed in ether solvent. Which statement below does not identify a safety concern associated w

nikdorinn [45]

Answer: A. Diethyl ether has a very low miscibility in wate

The fact that the diethyl ether is miscible or not in water does not imply a risk for the person who is working with this reagent in the laboratory.

However, the fact that diethyl ether forms explosive peroxides and that it is highly flammable implies that there is a risk of explosion when exposed to air and sunlight. On the other hand, as option C mentions, if a person inhales a large quantity of this reagent, they may lose consciousness and suffer some injury when fainting, due to the powerful anesthetic effect of this reagent. In conclusion, options B, C and D are statements that imply safety problems associated with the use of diethyl ether in the laboratory, while option A does not imply it.

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4 years ago