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A reaction is first order. If the initial reactant concentration is 0.0200 M, and 25.0 days later the concentration is 6.25 x 10

erastova [34]

A reaction is first order. If the initial reactant concentration is 0.0200 M, and 25.0 days later the concentration is 6.25 x 10-4 M, then its half-life is:

7 0

3 years ago

The value of delta for the [C_rF_6]^3- complex is 182 kJ/mol. Calculate the expected wavelength of the absorption corresponding

kirza4 [7]

Answer: Yes the absorb in the visible range.

Explanation:

The relationship between wavelength and energy of the wave follows the equation:

$E=\frac{Nhc}{\lambda}$

where,

$E$ = energy of the wave = 182 kJ/mol = 182000 J/mol

N = avogadro's number = $6.023\times 10^{23}$

h = plank constant = $6.6\times 10^{-34}Js^{-1}$

c = speed of light = $3\times 10^8m/s$

$\lambda$ = wavelength of the wave = ?

Putting all the values:

$182000=\frac{6.023\times 10^{23}\times 6.6\times 10^{-34}\times 3\times 10^8m/s}{\lambda}$

$\lambda=0.65\times 10^{-6}m=650nm$ $(1nm=10^{-9}m)$

The wavelength range for visible rays is 400 nm to 750 nm, thus the complex absorb in the visible range.

5 0

3 years ago

Ethanol is a common laboratory solvent and has a density of 0.789 g/ml. What is the mass, in grams, of 125 ml of ethanol?

olga55 [171]

The density of a material is its unique property by which a unknown material can be identified and also the impurity (if present) in a material can be concluded. Mathematically the density can be expressed as- $\frac{mass}{volume}$ . Thus from the mathematical expression we can say that the density is the mass per unit volume of a material. Here the density of ethanol is given 0.789 g/mL. Thus the weight of the 1 mL ethanol is 0.789g. Thus the weight of the 125 mL of ethanol will be (125×0.789) = 98.625 g.

3 0

4 years ago

What volume in liters, l, of solution should sven prepare if he wants to make a 5.00 m solution using 210.0 grams, g, of sodium

weeeeeb [17]

To make a 5.00 M solution using 210.0 grams, g, of sodium chloride, NaCl, we will use the formula of volume of solution in liters is equal to mole of solute per molarity of solution, which is 0.718 L.

Molarity (M) refers to the amount of a substance in a specific volume of solution. It is defined as the moles of a solute per liters of a solution. Molarity is also known as the molar concentration of a solution.

Molarity is given by the quotient,

Molarity = moles of solute/volume of solution in liters.

Now in order to get the molarity of the solution, we have to divide the moles of solute over the liters of solution. Since we are given the mass of the solute, we must first convert the mass of NaCl into moles with the help of the molar mass of NaCl as a conversion factor.

210 NaCl x ( 1 mol NaCl/ 58.44g NaCl) = 3.59 mol NaCl.

We already have the molarity of the solution that is 5.00 M. So the solution to find out the volume will be,

Volume of solution in liters = mole of solute/ molarity of solution,

That is 3.59 mol NaCl / 5M = 0.718 L

To learn more about Molarity, head here

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5 0

2 years ago

How would the lack of auxins affect plants' growth?

lidiya [134]

Answer:

I think it is B

Explanation:

3 0

3 years ago