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10 ejemplos de disoluciones identificando el soluto y el solvente y el tipo de disolucion que corresponde

Keith_Richards [23]

Answer:

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4 0

3 years ago

What pressure is required to achieve a co2 concentration of 7.90×10−2 m at 20∘c?

Savatey [412]

Answer:- 1.90 atm

Solution:- It is based on combined gas law equation, PV = nRT

In this equation, P is pressure, V is volume, n is moles of gas, R is universal gas constant and T is kelvin temperature.

If we divide both sides by V then:

$P=\frac{nRT}{V}$

We know that, molarity is moles per liter. So, in the above equation we could replace $\frac{n}{V}$ by molarity, M of the gas. The equation becomes:

P = MRT

T = 20 + 273 = 293 K

M = $7.9*10^-^2$

Let's plug in the values in the equation:

P = $(7.9*10^-^2)(0.0821)(293)$

P = 1.90 atm

So, the pressure of the gas is 1.90 atm.

7 0

3 years ago

1. Using the Slater rule, determine the effective nuclear charge of platinum.

AleksandrR [38]

Answer:

Z* = 3.55

Explanation:

Slater rule says that:

Z*= Z - S

Z* be the nuclear effective charge

Z is the nuclear charge

S is the shielding constant

First we write the electronic configuration of platinum: $1s^{2} 2s^{2} 2p^{6} 3s^{2} 3p^{6} 3d^{10} 4s^{2} 4p^{6} 4d^{10} 5s^{2} 5p^{6} 4f^{14} 5d^{9} 6s^{1}$

The first Slater rule says that we need to group:

$(1s^{2}) (2s, 2p)^{8} (3s, 3p)^{8} (3d^{10}) (4s, 4p)^{8} (4d^{10}) (5s, 5p)^{8} (4f^{14}) (5d^{9}) (6s^{1})$

The second rule says that the electrons to the right are not shielding, but we are going to solve the exercise for the last level (6s), so we don't have electrons to the right.

For the third rule we have two considerations, if is ns or np and if is nd or nf:

For our case, we have an electro that is in ns, so the rule says that

-electrons within same group shield 0.35, except the 1s which shield 0.30

-electrons within the n-1 group shield 0.85

-electrons within the n-2 or lower groups shield 1.00

Now we can proceed with the calculation:

The first consideration in the third rule does not apply as we only have one electron on this level.

The second consideration will be as follow for the level 5, where we have 17 electrons.

Finally the third consideration will be for levels 1, 2, 3 and 4, where we have 14 for 4f, 10 for 4d, 8 for 4s and 4p, 10 for 3d, 8 for 3s and 3p, 8 for 2s and 2p and finally 2 for 1s, which gives 60 electrons.

So the result for S=(60*1.00 + 17*0.85) = 74.45

And the equation is: Z* = 78 - 74.45

So Z* = 3.55

3 0

3 years ago

Which pair has the stronger ionic bond: - MgCl2 vs. NaCl2 - NaCl vs. LiCl

Rudiy27

Answer:

- NaCl vs. LiCl

5 0

3 years ago

What is the sequence in the formation of the Earth and the Universe?

Bezzdna [24]

Answer:

The Earth formed billions of years after the Universe formed

Explanation:

The "universe" is said to have been formed billions of year ago through an explosion. This was called the "Big Bang Theory." This lead to the expansion of the universe owing to its high temperature and density. After which, the universe cooled down. Galaxies and stars were then formed. Some of the stars died due to explosion, which then led to the creation of planets. Such formation of the planets happened around 4.5 billion years ago. This is 9.3 billions of years later than the universe was formed (13.8 billions of years ago). So, this explains the answer.

3 0

3 years ago