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3 years ago

Energy cannot be created or destroyed. Does the statement describe a scientific law?

Chemistry

1 answer:

LekaFEV [45]3 years ago

3 0

Yes, the law of thermodynamics, or Law of Conservation of Energy

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What is a serial dilution?

lord [1]

A serial dilution is the stepwise dilution of a substance in solution. Usually the dilution factor at each step is constant, resulting in a geometric progression of the concentration in a logarithmic fashion.

4 0

3 years ago

Give another mixture of liquids that is separated on an industrial scale by fractional

iren [92.7K]

Answer:

dna or diabeties can be separated

7 0

3 years ago

The activation energy for a reaction is changed from 184 kJ/mol to 59.0 kJ/mol at 600. K by the introduction of a catalyst. If t

11111nata11111 [884]

Answer:

The catalyzed reaction will take 2.85 seconds to occur.

Explanation:

The activation energy of a reaction is given by:

$k = Ae^{-\frac{E_{a}}{RT}}$

For the reaction without catalyst we have:

$k_{1} = Ae^{-\frac{E_{a_{1}}}{RT}}$ (1)

And for the reaction with the catalyst:

$k_{2} = Ae^{-\frac{E_{a_{2}}}{RT}}$ (2)

Assuming that frequency factor (A) and the temperature (T) are constant, by dividing equation (1) with equation (2) we have:

$\frac{k_{1}}{k_{2}} = \frac{Ae^{-\frac{E_{a_{1}}}{RT}}}{Ae^{-\frac{E_{a_{2}}}{RT}}}$

$\frac{k_{1}}{k_{2}} = e^{\frac{E_{a_{2}} - E_{a_{1}}}{RT}$

$\frac{k_{1}}{k_{2}} = e^{\frac{59.0 \cdot 10^{3}J/mol - 184 \cdot 10^{3} J/mol}{8.314 J/Kmol*600 K} = 1.31 \cdot 10^{-11}$

Since the reaction rate is related to the time as follow:

$k = \frac{\Delta [R]}{t}$

And assuming that the initial concentrations ([R]) are the same, we have:

$\frac{k_{1}}{k_{2}} = \frac{\Delta [R]/t_{1}}{\Delta [R]/t_{2}}$

$\frac{k_{1}}{k_{2}} = \frac{t_{2}}{t_{1}}$

$t_{2} = t_{1}\frac{k_{1}}{k_{2}} = 6900 y*1.31 \cdot 10^{-11} = 9.04 \cdot 10^{-8} y*\frac{365 d}{1 y}*\frac{24 h}{1 d}*\frac{3600 s}{1 h} = 2.85 s$

Therefore, the catalyzed reaction will take 2.85 seconds to occur.

I hope it helps you!

4 0

3 years ago

Match the theory to the statement that best describes it. 1. big bang it's like an inflating and deflating balloon that never st

otez555 [7]

1. big bang-the most accepted theory on the origin of the universe 
2. steady state-all is the same and will always stay the same 
3. oscillating universe-agrees with the big bang theory, but insists the universe expanded much quicker 
4. inflation-it's like an inflating and deflating balloon that never stops

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3 years ago

Read 2 more answers

A solution contains 11% by mass of sodium chloride. this means that __________.

d1i1m1o1n [39]

As a solution is contained with 11% by mass of sodium chloride, this will therefore conclude that the 100g of the solution is composed of the 11g of the sodium chloride. In which, the correct answer would be specified as letter c.

5 0

3 years ago