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3 years ago

Choose the ground state electron configuration for Cr3+.

Chemistry

1 answer:

alukav5142 [94]3 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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Describe the three main sub?atomic particles. Include mass (with units), charge and location for each.

Afina-wow [57]

Electron - negligible mass, negative charge, orbits the nucleus
Proton - 1 AMU, positive charge, in the nucleus
Neutron, 1 AMU, no charge, in the nucleus

5 0

3 years ago

A buffer solution is made that is 0.347 M in H2C2O4 and 0.347 M KHC2O4.

irga5000 [103]

Answer:

1. pH = 1.23.

2. $H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)$

Explanation:

Hello!

1. In this case, for the ionization of H2C2O4, we can write:

$H_2C_2O_4\rightleftharpoons HC_2O_4^-+H^+$

It means, that if it is forming a buffer solution with its conjugate base in the form of KHC2O4, we can compute the pH based on the Henderson-Hasselbach equation:

$pH=pKa+log(\frac{[base]}{[acid]} )$

Whereas the pKa is:

$pKa=-log(Ka)=-log(5.90x10^{-2})=1.23$

The concentration of the base is 0.347 M and the concentration of the acid is 0.347 M as well, as seen on the statement; thus, the pH is:

$pH=1.23+log(\frac{0.347M}{0.347M} )\\\\pH=1.23+0\\\\pH=1.23$

2. Now, since the addition of KOH directly consumes 0.070 moles of acid, we can compute the remaining moles as follows:

$n_{acid}=0.347mol/L*1.00L=0.347mol\\\\n_{acid}^{remaining}=0.347mol-0.070mol=0.277mol$

It means that the acid remains in excess yet more base is yielded due to the effect of the OH ions provided by the KOH; therefore, the undergone chemical reaction is:

$H_2C_2O_4(aq) +OH^-(aq)\rightarrow HC_2O_4^-(aq)+H_2O(l)$

Which is also shown in net ionic notation.

Best regards!

4 0

3 years ago

The table below shows the dimensions of two colored cubes.

Lynna [10]

Answer:

Red, because it has less volume and more amount of matter.

Explanation:

3 0

3 years ago

The number of un paired electrons in the outer subshell of a cl atom is

Tatiana [17]

1 is the number of unpaired electrons in the outer subshell of a Cl atom

3 0

3 years ago

What is the molarity of a solution that contains 200. 0 g of lithium chloride in 450 mL? molar mass of chloride= 42. 394g/mol

alisha [4.7K]

Explanation:

Sol. 450 ml there is LiCl 200 g

Sol. 1000 ml there is LiCl 200/450×1000

= 444.44 g

Molar = g/molar mass = 444.44/42.394 = 10.48 M

3 0

2 years ago