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2 years ago

Choose the ground state electron configuration for Cr3+.

Chemistry

1 answer:

alukav5142 [94]2 years ago

5 0

Answer:

b) [Ar]4s²3d1¹

Explanation:

Chromium, Cr, is the atom with atomic number 24 (That is, 24 protons).

A Cr³⁺ contains 3 electrons less than number of protons. That is 21electrons.

The Argon, Ar, contains 18 electrons. That means the electronic configuration of Cr³⁺ contains 3 electrons more than Ar.

Following the Hund's rule, these three electrons will occupy the 4S orbital (2 electrons) and the 2d orbital (1 electron).

Thus, right solution is:

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A 125g metal block at a temperature of 93.2 degrees Celsius was immersed in 100g of water at 18.3 degrees Celsius. Given the spe

nikitadnepr [17]

Answer:

$\large \boxed{34.2\, ^{\circ}\text{C}}$

Explanation:

There are two heat transfers involved: the heat lost by the metal block and the heat gained by the water.

According to the Law of Conservation of Energy, energy can neither be destroyed nor created, so the sum of these terms must be zero.

Let the metal be Component 1 and the water be Component 2.

Data:

For the metal:

$m_{1} =\text{125 g; }T_{i} = 93.2 ^{\circ}\text{C; }\\C_{1} = 0.900 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}$

For the water:

$m_{2} =\text{100 g; }T_{i} = 18.3 ^{\circ}\text{C; }\\C_{2} = 4.184 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}$

$\begin{array}{rcl}\text{Heat lost by metal + heat gained by water} & = & 0\\q_{1} + q_{2} & = & 0\\m_{1}C_{1}\Delta T_{1} + m_{2}C_{2}\Delta T_{2} & = & 0\\\text{125 g}\times 0.900 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$} \times\Delta T_{1} + \text{100 g} \times 4.184 \text{ J$^{\circ}$C$^{-1}$g$^{-1}$}\Delta \times T_{2} & = & 0\\112.5\Delta T_{1} + 418.4\Delta T_{2} & = & 0\\112.5\Delta T_{1} & = & -418.4\Delta T_{2}\\\Delta T_{1} & = & -3.719\Delta T_{2}\\\end{array}$

$\Delta T_{1} = T_{\text{f}} - 93.2 ^{\circ}\text{C}\\\Delta T_{2} = T_{\text{f}} - 18.3 ^{\circ}\text{C}$

$\begin{array}{rcl}\Delta T_{1} & = & -3.719\Delta T_{2}\\T_{\text{f}} - 93.2 ^{\circ}\text{C} & = & -3.719 (T_{\text{f}} - 18.3 ^{\circ}\text{C})\\T_{\text{f}} - 93.2 ^{\circ}\text{C} & = & -3.719T_{\text{f}} + 68.06 ^{\circ}\text{C}\\4.719T_{\text{f}} & = & 161.3 ^{\circ}\text{C}\\T_{\text{f}} & = & \mathbf{34.2 ^{\circ}}\textbf{C}\\\end{array}\\\text{The final temperature of the block and the water is $\large \boxed{\mathbf{34.2\, ^{\circ}}\textbf{C}}$}$

3 0

3 years ago

Which of the following examples illustrates a number that is correctly rounded to three significant figures?

Naily [24]

Answer:

c. 20.0332 g to 20,0 g

Explanation:

A significant figure is each of the digits of a number that are used to express it to the required degree of accuracy, starting from the first non-zero digit, with the exception of the trailing zeros.

<em>Which of the following examples illustrates a number that is correctly rounded to three significant figures? </em>

a. 109 526 g to 109 500 g. NO. The rounded number has 4 significant figures: 109 500.

b. 0.03954 g to 0.040 g. NO. The rounded number has 2 significant figures: 0.040.

c. 20.0332 g to 20.0 g. YES. The rounded number has 3 significant figures: 20.0.

d. 04.05438 g to 4.054 g. NO. The rounded number has 4 significant figures: 4.054.

e. 103.692 g to 103.7g. NO. The rounded number has 4 significant figures: 103.7.

8 0

3 years ago

A person has a mass of 63.4kg. What is the weight in pounds?

Evgen [1.6K]

If a person weighs 63.4 KG they will weigh 139.773 but if you estimate it which in most cases you do it would be 139.8 :)

3 0

8 months ago

Are my electron configurations correct and if not explain why

Makovka662 [10]

Configuration of carbon is 1s2 2s2 2p2 and the rest of all is correct

3 0

2 years ago

The force of 75 N must overcome in order to get the truck to start moving. What type of friction must be overcome?

Tamiku [17]

Answer:

Static Friction.

Explanation:

Friction is the force that resists the relative motion between the surfaces sliding against each other.

Static friction is friction between objects that are not in relative motion with each other.

The coefficient of static friction, typically denoted as μs,

Static friction arises due to surface roughness( relative term)

The static friction force can be overcome by an applied maximum force

F max = μs x N

N= normal force

Any force smaller than F max attempting to slide one surface over the other is opposed by a frictional force of equal magnitude and opposite direction.

Any force larger than F max overcomes the force of static friction and causes sliding to occur.

This maximum force is sometimes called the limiting value also. Here that value is 75 N.

3 0

2 years ago