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3 years ago

10. In which of the following is the symbol for the ion and the total number of electrons it contains given correctly?

Chemistry

1 answer:

dalvyx [7]3 years ago

5 0

Answer:

10. D

9. A

8. A or B

Explanation:

10. Calcium has 20 electrons, but the Calcium ion has 18 electrons.

9. The mass of electrons are negligible.

8. Electrons have a very small mass where some consider it to have no mass.

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Water's ability to dissolve a wide variety of molecules is important, but more important is the hydrophobic effect, which drives

Sliva [168]

Answer:

d. Hydrophobic molecules are attracted to each other.

Explanation:

The term “hydrophobic effect” is associated with the spontaneous tendency of macromolecules, such as proteins, to prefer a conformation in an aqueous medium, with hydrophobic groups facing the interior of the mac romolecule, favoring attractive intramolecular interactions, and hydrophilic groups exposed on the surface, for maximize interactions with water molecules in the medium. This is because the hydrophobic molecules are attracted to each other, allowing them to turn inward.

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3 years ago

Dinitrogen tetraoxide, N2O4, decomposes to nitrogen dioxide, NO2, in a first-order process. If k = 1.5 x 103 s-1 at 5 ºC and k =

Arada [10]

Answer:

The activation energy for the decomposition = 33813.28 J/mol

Explanation:

Using the expression,

$\ln \dfrac{k_{1}}{k_{2}} =-\dfrac{E_{a}}{R} \left (\dfrac{1}{T_1}-\dfrac{1}{T_2} \right )$

Wherem

$k_1\ is\ the\ rate\ constant\ at\ T_1$

$k_2\ is\ the\ rate\ constant\ at\ T_2$

$E_a$ is the activation energy

R is Gas constant having value = 8.314 J / K mol

Thus, given that, $E_a$ = ?

$k_2=4.0\times 10^3s^{-1}$

$k_1=1.5\times 10^3s^{-1}$

$T_1=5\ ^0C$

$T_2=25\ ^0C$

The conversion of T( °C) to T(K) is shown below:

T(K) = T( °C) + 273.15

So,

T = (5 + 273.15) K = 278.15 K

T = (25 + 273.15) K = 298.15 K

$T_1=278.15\ K$

$T_2=298.15\ K$

So,

$\ln \frac{1.5\times 10^3}{4.0\times 10^3}\:=-\frac{E_{a}}{8.314}\times \left(\frac{1}{278.15}-\frac{1}{298.15}\right)$

$E_a=-\ln \frac{1.5\times \:10^3}{4.0\times \:10^3}\:\times \frac{8.314}{\left(\frac{1}{278.15}-\frac{1}{298.15}\right)}$

$E_a=-\frac{8.314\ln \left(\frac{1.5\times \:10^3}{4\times \:10^3}\right)}{\frac{1}{278.15}-\frac{1}{298.15}}$

$E_a=-\frac{689483.53266 \ln \left(\frac{1.5}{4}\right)}{20}$

$E_a=33813.28\ J/mol$

The activation energy for the decomposition = 33813.28 J/mol

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3 years ago

Would the following configuration represent

makvit [3.9K]

Answer:

Excited state

Explanation:

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3 years ago

After swimming in the ocean for several hours, the swimmers noticed that their fingers appeared to be very wrinkled or shriveled

MatroZZZ [7]

The answer is hypertonic. In osmosis, water molecules move from a hypotonic solution to the hypertonic solution, through a semipermeable membrane. This occurs until both solutions become isotonic relative to each other. In osmosis, only the movement of water molecules occurs since the ions are large enough to pass through the pores of the semipermeable membrane, in this case, the cell membrane. Due to loss of water in the process of osmosis, the cells in the fingers of the swimmers shrunk hence looked shriveled.

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3 years ago

The specific shape that an electron moves in inside a sub-level_____

VashaNatasha [74]

Answer:

The specific shape that an electron moves in inside a sub-level shell.

6 0

2 years ago