1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
shtirl [24]
3 years ago
8

A reaction has a rate constant of 1.15 x 10^−2 /s at 400K and 0.685 /s at 450K.

Chemistry
1 answer:
n200080 [17]3 years ago
4 0

Answer:

a) the activation barrier = 122.3 kJ/mol

b) The rate constant at 425 K = 0.1001 /s

Explanation:

Step 1: Data given

Rate constant k1 = 1.15 * 10^−2 /s  at 400K (= T1)

Rate constant k2 = 0.685 /s at 450K (=T2)

Step 2: Determine the activation barrier for the reaction.

To determine the activation energy we will use the two-point Arrhenius equation:

ln(k₂/k₁) =  (Ea/R)((1/T1) - (1/T2))

⇒ with Ea = the activating energy

 ⇒ with R = the gas constant = 8.314 J/mol* K

⇒ with k1  = rate constant 1 = 1.15 *10^-2 /s

⇒ with T1 = Temperature 1 = 400 K

⇒ with k2 = rate constant 2 = 0.685/s

⇒ with T2 = temperature 2 = 450 K

= - (Ea/R)(T₁ - T₂)/T₁T₂

Ea = (R*ln (k2/k1)) / ((1/T1)- (1/T2))

Ea = (8.314* ln(0.685/0.0115)) / ((1/400) - (1/450))

Ea = 122327.6 = 122.3 kJ/mol

B) What is the value of the rate constant at 425 K

For rate constant at 425 K.

Substitute the value of activation energy as 122327.6 J/mol, initial temperature as 400 K, final temperature as 425 K, rate constant at 400 K

1/T1   - 1/ T3   = 1/400   - 1 /425    = 1.47*10^-4

⇒ with T1 = the initial temperature = 400 K

⇒ with k1 = the rate constant at 400 K = 1.15 * 10^-2 /s

⇒ with T3 = the nex temperature = 425 K

⇒ with k3 = the rate constant at 425 K

ln(k3/k1) = Ea/R * ((1/T1)- (1/ T3))

⇒ with k3 = the rate constant at 425 K

⇒ with T3 = 425 K

k3/k1 = e^(Ea/R * ((1/T1)- (1/ T3)))

k3 = k1* e^(Ea/R * ((1/T1)- (1/ T3)))

k3 = 0.0115 * e^(122327.6/8.314 * (1.4710^-4))

k3 = 0.0115* e^2.1643

k3 = 0.1001 /s

You might be interested in
Between Lab Period 1 and Lab Period 2, design a separation scheme for all 4 cations. Use the results of your preliminary tests a
fiasKO [112]

Answer:

                    SEPARATION SCHEME FOR  CATIONS

GIVEN  CATIONS : Ag^{+} \ ,  Fe^{3+} , Cu^{2+}, Ni^{2+}

     

    Step 1:   Add 6mol/dm^3 of HCl to the mixture solution

    Result : This would cause a precipitate of AgCl to be formed

    Reaction :  Ag^{+} _{(aq)} + Cl^{-} _{(aq)}  ---------> AgCl(ppt)

    Step 2 : Next is to remove the precipitate and add H_2S to the remaining          

                 solution in the presence of 0.2 \ mol/dm^3 of HCl

     Result : This would cause a precipitate of CuS to be formed

     Reaction :  Cu^{2+}_{(aq)} + S^{2-}_{(aq)} ------> Cu_2S(ppt)

 

     Step 3: Next remove the precipitate then add 6 \ mol/dm^3 of aqueous      

                 NH_3 (NH_3 \cdot H_2 O) , process the solution in a centrifuge,when the  

                 process  is done then sort out the  precipitate from the  solution

                 Now this precipitate is   Fe(OH)_3 and the remaining solution

                contains  (Ni (NH_3)_6)

                 Next take out the precipitate to a different beaker and add HCl

                to it   this will dissolve it, then add a drop of NH_4SCN this will

                form  a precipitate  Fe(SCN)_{6}^{3-} which will have the color of

                 blood  indicating the presence of Fe^{3+}

             

   Reaction :   F^{3+}_{(aq)} + 30H^-_{(aq)} --------->Fe(OH)_3_{(aq)}

                        Fe (OH)_{(s)} _3  + 3H^{+}_{aq} -------> Fe^{3+}_{aq} + 3H_2O_{(l)}

                         Fe^{3+} + 6SCN^{-} -----> Fe(SCN)_6 ^{3-}

                      Now the remaining mixture contains Ni^{2+}

     

       

Explanation:

6 0
3 years ago
Which substance is most likely a lipid? -long chains of molecules composed of carbon, hydrogen, and oxygen atoms -compounds that
gulaghasi [49]

Answer:

The answer is

Explanation:

- A nonpolar organic compound that is insoluble in water

3 0
3 years ago
A metal ion Mⁿ⁺ has a single electron. The highest energy line in its emission spectrum occurs at a frequency of 2.961 x 10¹⁶ Hz
Whitepunk [10]

Answer:

z≅3

Atomic number is 3, So ion is Lithium ion (Li^+)

Explanation:

First of all

v=f*λ

In our case v=c

c=f*λ

λ=c/f

where:

c is the speed of light

f is the frequency

\lambda=\frac{3*10^8}{2.961*10^{16}}\\ \lambda=1.01317*10^{-8} m

Using Rydberg's Formula:

\frac{1}{\lambda}=R*z^2*(\frac{1}{n_1^2}-\frac{1}{n_2^2})

Where:

R is Rydberg constant=1.097*10^7

z is atomic Number

For highest Energy:

n_1=1

n_2=∞

\frac{1}{1.01317*10^{-8}}=1.097*10^{7}*z^2*(\frac{1}{1^2}-\frac{1}{\inf})\\z^2=8.99\\z=2.99

z≅3

Atomic number is 3, So ion is Lithium ion (Li^+)

3 0
3 years ago
Question 3<br> What part of a water molecule is the negatively charged side?
aleksandr82 [10.1K]

Answer:

The oxygen atom in water has a negative charge.

<h2>Definitions:</h2>

Polar molecule: A molecule in which the centroid of the positive charges is different from the centroid of the negative charges.

Oxygen: A colorless, odorless, gaseous element constituting about one-fifth of the volume of the atmosphere and present in a combined state in nature. It is the supporter of combustion in air and was the standard of atomic, combining, and molecular weights until 1961, when carbon 12 became the new standard. Symbol: O; atomic weight: 15.9994; atomic number: 8; density: 1.4290 g/l at 0°C and 760mm pressure.

Water: A transparent, odorless, tasteless liquid, a compound of hydrogen and oxygen, H2O, freezing at 32°F or 0°C and boiling at 212°F or 100°C. that in more or less impure state constitutes rain, oceans, lakes, rivers, etc.: it contains 11.188 percent hydrogen and 88.812 percent oxygen, by weight.

Hydrogen: A colorless, odorless, flammable gas that combines chemically with oxygen to form water: the lightest of the known element. Symbol: H; atomic weight: 1.00797; atomic number: 1; density: 0.0899 g/l at 0°C and 760 mm pressure.

Atom: Am atom is the smallest constituent particle of a chemical element which has the properties of that element. They re comprised of at least an electron and a portion, as is the case for Hydrogen. Atoms of all other elements however, contain at least one neutron.

Proton: A positively charged elementary particle that is a fundamental constituent of all atomic nuclei. It is the lightest and most stable baryon, having a charge equal in magnitude to that of the electron, a spin of 1/2, and a mass of 1.673 × 10-27kg. Symbol: P.

Electron: An elementary particle that is a fundamental constituent of matter, having a negative charge of 1.602 × 10-19 coulombs, ha mass of 9.108 × 10-31 kilograms, and spin of 1/23, and existing independently or as the component outside the nucleus of an atom.

Neutron: An elementary particle having no charge, mass slightly greater than that of a proton, and spin of 1/2: a constituent of the nuclei of all atoms except those of hydrogen. Symbol: n.

<h2>What is a negative charge?</h2>

A object has a negative charge when it consists of more electrons than protons.

With a partial positive charge on 2 Hs and a partial negative charge on oxygen, water molecules are polar molecules.

Actually, two hydrogen atoms and the core oxygen atom of water are covalently connected. Due to its greater electronegative nature than hydrogen, oxygen pulls the bound electron pair in the middle of the atom toward it.

When illustrating higher electron densities over oxygen, partial negative charge is used, whereas partial positive charge is used to illustrate lower densities over hydrogen atoms.

#SPJ2

3 0
1 year ago
Convert 9.79 kilograms (kg) to decagrams (dg).
kap26 [50]

Answer:

C) 979 dg

Explanation:

1 Decagram = 0.01 Kilogram, and 1 kilogram = 100 Decagram.

Hope this helps :)

6 0
2 years ago
Other questions:
  • WORTH 99 POINTS
    6·2 answers
  • What is the density of carbon dioxide gas if 0.196g occupies a volume of 100mL?
    9·1 answer
  • What is the Domain with four kingdoms or organisms that have cells with nuclei?
    6·1 answer
  • Need this asap , help please
    5·1 answer
  • Given the elements chlorine, iodine, oxygen, bromine, and fluorine, organize by increasing atomic size (atomic radius). Justify
    5·1 answer
  • Who won't free Brainliest
    8·2 answers
  • 2. What happens when hydrochloric acid (HCl) is added to the solution? Do the relative concentrations of H+, CH3COOH, or
    12·2 answers
  • How did max planck contribute to the modern atomic theory?
    9·2 answers
  • what are the three molecules that are attached to the plasma membrane, and what are their roles/ functions?
    5·1 answer
  • Colorea los recuadros que representan la acciones viables para usar racionalmente los recursos y contaminar menos
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!