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3 years ago

Select the correct answer from each drop-down menu.

Chemistry

2 answers:

seraphim [82]3 years ago

5 0

1. protons and neutrons

2. electrons

liraira [26]3 years ago

4 0

Answer:

Protons and neutrons, Electrons

Explanation:

Protons and electrons are found in the center of the nucleus. The atomic mass is the summation of the number of neutrons and protons. Electrons orbit around the nucleus in an atom. The atomic number is equal to the number of electrons which is also equal to the number of protons.

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When compounds are formed, will its heat give off?

mariarad [96]

Answer: It depends on the type of chemical reaction that formed the compound.

Explanation:

Exothermic reactions give off the heat to the reaction environment, so the compound feels hotter.

Endothermic reactions absorb the heat from the reaction environment and the compound feels cooler.

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3 years ago

Find the number of moles of argon in 364 grams of argon.

serg [7]

Answer:D. 9.1 mole Ar

Explanation:

364 g Ar x 1 mole Ar / 40 g Ar

= 9.1 moles Ar

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3 years ago

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aksik [14]

Iodine and Calcium is the correct answer

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3 years ago

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A 52.0-mL volume of 0.35 M CH3COOH (Ka=1.8×10−5) is titrated with 0.40 M NaOH. Calculate the pH after the addition of 23.0 mL of

Georgia [21]

NaOH reacts with CH3COOH in 1:1 molar ratio to produce CH3COONa

NaOH + CH3COOH → CH3COONa + H2O

Mol CH3COOH in 52.0mL of 0.35M solution = 52.0/1000*0.35 = 0.0182 mol CH3COOH

Mol NaOH in 19.0mL of 0.40M solution = 19.0/1000*0.40 = 0.0076 mol NaOH

These will react to produce 0.0076 mol CH3COONa and there will be 0.0182 - 0.0076 = 0.0106 mol CH3COOH remaining in solution unreacted . Total volume of solution = 52.0+19.0 = 71mL or 0.071L

Molarity of CH3COOH = 0.0106/0.071 = 0.1493M

CH3COONa = 0.0076 / 0.071 = 0.1070M

pKa acetic acid = - log Ka = -log 1.8*10^-5 = 4.74.

pH using Henderson - Hasselbalch equation:

pH = pKa + log ([salt]/[acid])

pH = 4.74 + log ( 0.1070/0.1493)

pH = 4.74 + log 0.717

pH = 4.74 + (-0.14)

pH = 4.60.

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3 years ago

The coordination sphere of a complex consists of ________. The coordination sphere of a complex consists of ________. the ligand

sammy [17]

Answer:

The coordination sphere of a complex consists of the central metal ion and the ligands bonded to it.

Explanation:

The Coordination Compounds are sets of a central metal ion attached to a group of molecules or ions that surround it. They are also called metal complexes or simply complexes. Then they are compounds that have a central atom surrounded by a group of molecules or ions, the latter called ligands.

The central atom must have empty orbitals capable of accepting pairs of electrons, with the transition metals being the ones with the greatest tendency. Because of this, they can act as Lewis acids (electron pair acceptors). The ligands have unshared electron pairs, then acting as Lewis bases (electron pair donors).

When forming a complex, it is said that the ligands coordinate to the metal and the central metal and the ligands attached to it constitute the coordination sphere of the complex.

Finally, the coordination sphere of a complex consists of the central metal ion and the ligands bonded to it.

5 0

3 years ago