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3 years ago

What are the only elements that exist in nature as uncombined

Chemistry

1 answer:

mario62 [17]3 years ago

5 0

Answer:

The noble gases (Argon, Neon, Xenon, Helium, Krypton, Radon)

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How are different natural disasters related? What different causes and effects of natural disasters do you know about?

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2 years ago

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Given the molar absorptivity for a species X of 1600 M-1cm-1 at a wavelength of 270 nm, and 400 M-1cm-1 at a wavelength of 540 n

Andre45 [30]

Answer:

Explanation:

From the given information:

At wavelength = 270 nm

$\varepsilon x_1 = 1600 \ m^{-1} \ cm^{-1} \\ \\ \varepsilon y_1 = 200 \ m^{-1} \ cm^{-1}$

At 270 nm

Suppose x is said to be the solution for the concentration of x and y to be the solution for the concentration of y;

Then:

$\varepsilon x_1 \ l + \varepsilon y_1 \ l= 0.5 \\ \\ A = A_1 + A_2$

$1600 xl + 200 yl= 0.5$

Divide both sides by 200

$8xl + yl = \dfrac{0.5}{200}$

$8x + y = \dfrac{0.5}{200}l$

Use l = 1cm (i.e the standard length)

Then;

$8x + y = \dfrac{0.5}{200} ---- (1)$

For 540 nm:

$\varepsilon x_2 x \ l + \varepsilon y_2 y \ l= 0.5 \\ \\ 40 xl + 800 yl = 0.5$

$x + 20 y = \dfrac{0.5}{400 \ l}$

since l = 1

$x + 20 y = \dfrac{0.5}{400 \ } --- (2)$

Equating both (1) and (2) together, we have:

$8x + y - 8x - 160 y = \dfrac{0.5}{200} - \dfrac{0.5 \times 8}{400} \\ \\ \implies - 159 y = \dfrac{0.5}{200} ( 1 - \dfrac{8}{2}) \\ \\ -159 y = \dfrac{-0.5 \times 3}{200} \\ \\ 159 \ y = 0.0075 \\ \\ y = \dfrac{0.0075}{159} \\ \\ y = 0.00004716 \\ \\ y = 4.7 \times 10^{-5 } \ M$

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3 years ago

Given the equilibrium: A+B <--> C. The greatest concentration of C would be produced if the equilibrium constant of the re

Ad libitum [116K]

Answer: The greatest concentration of C would be produced if the equilibrium constant of the reaction is equal to $1\times 10^9$

Explanation:

Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as $K_c$

For the given chemical reaction:

$A+B\rightarrow C$

The expression for $K_c$ is written as:

$K_c=\frac{[C]}{[A][B]}$

Thus higher is the value of $K_c$ , higher will be the concentration of C. Thus the greatest concentration of C would be produced if the equilibrium constant of the reaction is equal to $1\times 10^9$

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3 years ago