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Law Incorporation [45]
3 years ago
11

I need help with this ​

Chemistry
1 answer:
Maurinko [17]3 years ago
4 0
What’s the question
You might be interested in
What is the daughter nucleus (nuclide) produced when 227th undergoes alpha decay?
Elina [12.6K]

Answer: -

²²³Ra is the daughter nuclide produced when ²²⁷Th undergoes alpha decay

Explanation: -

When alpha decay occurs, the mass number of the parent decreases by 4 and the atomic number decreases by 2.

Mass number of ²²⁷Th =227

Atomic number of ²²⁷Th = 90

Mass number of daughter = 227 - 4 = 223

Atomic number of daughter = 90 - 2 = 88

88 is the atomic number of Ra Radium.

Thus the daughter is ²²³Ra

6 0
3 years ago
Consider the generic reaction: 2 A(g) + B(g) → 2 C(g). If a flask initially contains 1.0 atm of A and 1.0 atm of B, what is the
irina1246 [14]

Answer:

b. 1.5 atm.

Explanation:

Hello!

In this case, since the undergoing chemical reaction suggests that two moles of A react with one moles of B to produce two moles of C, for the final pressure we can write:

P=P_A+P_B+P_C

Now, if we introduce the stoichiometry, and the change in the pressure x we can write:

P=1.0-2x+1.0-x+2x

Nevertheless, since the reaction goes to completion, all A is consumed and there is a leftover of B, and that consumed A is:

x=\frac{1.0atm}{2}=0.5atm

Thus, the final pressure is:

P=1.0-2(0.5)+1.0-(0.5)+2(0.5)\\\\P=1.5atm

Therefore the answer is b. 1.5 atm.

Best regards!

3 0
3 years ago
Describe the difference between accuracy and precision. How do these two concepts relate to the idea of significant digits?
Soloha48 [4]

Answer:

Accuracy of a measured value refers to how close a measurement is to the correct value. The uncertainty in a measurement is an estimate of the amount by which the measurement result may differ from this value. Precision of measured values refers to how close the agreement is between repeated measurements.

Explanation:

3 0
2 years ago
If element A is in Group 13 and element B is in Group 17, which ions will be formed when A and B react together?
Kobotan [32]

Answer:

A3+ and B-

Explanation:

Elements in group 13 have outermost electron configuration, ns2np1 hence they form trivalent positive ions.

Elements in group 17 have outermost electron configuration ns2np5 hence they form univalent negative ions.

This implies that, if element A is in Group 13 and element B is in Group 17, the ions formed are A3+ and B-.

8 0
2 years ago
Is selenium tetrafluoride an ionic or covalent bond?
nasty-shy [4]

Answer:

Synthesis

The first reported synthesis of selenium tetrafluoride was by Paul Lebeau in 1907, who treated selenium with fluorine:[1]

Se + 2 F2 → SeF4

A synthesis involving more easily handled reagents entails the fluorination of selenium dioxide with sulfur tetrafluoride:[2]

SF4 + SeO2 → SeF4 + SO2

An intermediate in this reaction is seleninyl fluoride (SeOF2).

Other methods of preparation include fluorinating elemental selenium with chlorine trifluoride:

3 Se + 4 ClF3 → 3 SeF4 + 2 Cl2

Structure and bonding

Selenium in SeF4 has an oxidation state of +4. Its shape in the gaseous phase is similar to that of SF4, having a see-saw shape. VSEPR theory predicts a pseudo-trigonal pyramidal disposition of the five electron pairs around the selenium atom. The axial Se-F bonds are 177 pm with an F-Se-F bond angle of 169.2°. The two other fluorine atoms are attached by shorter bonds (168 pm), with an F-Se-F bond angle of 100.6°. In solution at low concentrations this monomeric structure predominates, but at higher concentrations evidence suggests weak association between SeF4 molecules leading to a distorted octahedral coordination around the selenium atom. In the solid the selenium center also has a distorted octahedral environment.

Reactions

In HF, SeF4 behaves as a weak base, weaker than sulfur tetrafluoride, SF4 (Kb= 2 X 10−2):

SeF4 + HF → SeF3+ + HF2−; (Kb = 4 X 10−4)

Ionic adducts containing the SeF3+ cation are formed with SbF5, AsF5, NbF5, TaF5, and BF3.[3] With caesium fluoride, CsF, the SeF5− anion is formed, which has a square pyramidal structure similar to the isoelectronic chlorine pentafluoride, ClF5 and bromine pentafluoride, BrF5.[4] With 1,1,3,3,5,5-hexamethylpiperidinium fluoride or 1,2-dimethylpropyltrimethylammonium fluoride, the SeF62− anion is formed. This has a distorted octahedral shape which contrasts to the regular octahedral shape of the analogous SeCl62−. [5]

Explanation:

4 0
2 years ago
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