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3 years ago

What happen when two objects at different temperatures touch? Name one place where it occurs in earths system

Chemistry

2 answers:

Pavel [41]3 years ago

4 0

I suppose an example could technique be fog.

Lady bird [3.3K]3 years ago

3 0

Heat is exchanged until thermal equilibrium is reached.
It occurs basically everywhere.

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A highly polar molecule that contains a weak bond between a hydrogen atom and another element would be

sleet_krkn [62]

A highly polar molecule that contains a weak bond between a hydrogen atom and another element would be a strong acid.

8 0

4 years ago

The initial reaction rate for the elementary reaction 2A + B → 4C was measured as a function of temperature when the concentrati

Artist 52 [7]

Complete Question

The complete question is shown on the first uploaded image

Answer:

a) The activation energy is 124.776 $\frac{kJ}{mole}$

b) The frequency factor is 1.77 × $10^{18}$

c) The rate constant is 0.00033 $(\frac{dm^{3} }{mole} )^{2}$ $\frac{1}{s}$

Explanation:

From the question the elementary reaction for A and B is given as

2A + B → 4C

The rate equation the elementary reaction is

- $r_{A}$ = $k$ $[A]^{2}$ $[B]$

= $k[2]^{2}[1.5]$

= 6k

$k = \frac{-r_{A} }{6}$

When temperature changes, the rate constant change an this causes the rate of reaction to change as shown on the second uploaded image.

The relationship between temperature and rate constant can be deduced from these equation

$k = Aexp(-\frac{E_{a} }{RT} )$

taking ln of both sides we have

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

Considering the graph for the rate constant $ln k$ and $(\frac{1}{T} )$ the slope from the equation is $-(\frac{E_{a} }{R})$ and the intercept is $ln A$

From the given table we can generate another table using the equation above as shown on the third uploaded image

The graph of $ln k$ vs $(\frac{1}{T} )$ is shown on the fourth uploaded image

From the graph we can see that the slope is $-(\frac{E_{a} }{R} ) = - 15008$

Now we can obtain the activation energy $E_{a}$ by making it the subject in the equation also generally R which is the gas constant is $8.145 \frac{J}{kmole}$

$E_{a} = 15008 × 8,3145\frac{J}{molK}$

$= 124\frac{KJ}{mole}$

Hence the activation energy is $= 124\frac{KJ}{mole}$

b) From the graph its intercept is $ln A = 42.019$

$A = exp(42.019)$

$=1.77 × 10^{18}$

Hence the frquency factor A is $=1.77 × 10^{18}$

c) From the equation of rate constant

$lnk =ln A - (\frac{E_{a} }{R}) \frac{1}{T}$

We have

$ln k = 42.019 - 15008 * (\frac{1}{300} )$

$k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

Hence the rate constant is $k = 0.00033(\frac{dm^{3} }{mole} )^{2} \frac{1}{s}$

6 0

3 years ago

A rectangular box has a length of 12 cm, a width of 20 cm, and a

enot [183]

Answer:

1100mL

Explanation:

V of a rectangular prism = l*w*h

= 12cm*20cm*5cm

=1100cm^3

1 cm^3 = 1mL

so 1100cm^3 = 1100mL

8 0

3 years ago

What is the OH- in a solution with a pOH of 5.17

harina [27]

Answer:

1 oxygen 1 hydrogen hydrogen peroxide I think

5 0

3 years ago

Morphine is an effective pain killer but is also highly addictive. calculate the ph of a 0.115 m solution of morphine if its pkb

VMariaS [17]

Answer is: pH value of morphine is 10.64.
Chemical reaction: C₁₇H₁₉NO₃ + H₂O → C₁₇H₁₉NO₃H⁺ +OH⁻.
Kb(C₁₇H₁₉NO₃) = 10∧(-5,79) = 1,62·10⁻⁶.
c(C₁₇H₁₉NO₃) = 0,115 M.
Kb(C₁₇H₁₉NO₃) = c(OH⁻) · c(C₁₇H₁₉NO₃H⁺) ÷ c(C₁₇H₁₉NO₃).
c(OH⁻) = c(C₁₇H₁₉NO₃H⁺) = x.
1,62·10⁻⁶ = x² ÷ (0,115 - x).
Solve quadratic equation: x = c(OH⁻) = 0,000431 M.
pOH = -log(0,000431 M) = 3,36.
pH = 14 - 3,36 = 10,64.

5 0

3 years ago