224/88Ra+4/2He+? find the missing isotope

Identify the dominant intermolecular attraction in bh3.

k0ka [10]

The molecule BH3 is trigonal planar, with B in the center and H in the three vertices. Ther are no free electrons. All the valence electrons are paired in and forming bonds.

There are four kind of intermolecular attractions: ionic, hydrogen bonds, polar and dispersion forces.

B and H have very similar electronegativities, Boron's electronegativity is 2.0 and Hydrogen's electronegativity is 2.0.

The basis of ionic compounds are ions and the basis of polar compounds are dipoles.

The very similar electronegativities means that B and H will not form either ions or dipoles. So, that discards the possibility of finding ionic or polar interactions.

Regarding, hydrogen bonds, that only happens when hydrogen bonds to O, N or F atoms. This is not the case, so you are sure that there are not hydrogen bonds.

When this is the case, the only intermolecular force is dispersion interaction, which present in all molecules.

Then, the answer is dispersion interaction.

6 0

3 years ago

What do you expect from a hurricane?

blsea [12.9K]

Depending in the category of the Hurricane, you make experience different levels of wind power and destruction. Hurricanes only have 5 categories ranking from Category 1 to Category 5. The smallest category is category 1 making category 5 the largest. The bigger the category, the more wind or destruction you'll experience.

6 0

3 years ago

Read 2 more answers

How does the electron-cloud model describe electrons?

Sav [38]

Answer:

C. An electron has a high probability of being in certain regions.

Explanation:

In the electron cloud model, there are no electron-orbits around the nucleus but a cloud. This cloud has various densities with respect to distance from the nucleus. The most dense region of the cloud (which is the region close to the nucleus) is where electrons has the highest probability of existence.

The model explains that an electron a greater chance of being in the region closer to the nucleus. Thus, an electron has a high probability of being in certain region of the cloud about the central nucleus. And an electrostatic force exists between the nucleus and the electrons.

7 0

3 years ago

Dissolution of KOH, ΔHsoln:

swat32

Using Hess's law we found:

1) By adding reaction 10.2 with the reverse of reaction 10.1 we get reaction 10.3:

KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) ΔH (10.3)

2) The ΔHsoln must be subtracted from ΔHneut to get the total change in enthalpy (ΔH).

The reactions of dissolution (10.1) and neutralization (10.2) are:

KOH(s) → KOH(aq) ΔHsoln (10.1)

KOH(s) + HCl(aq) → H₂O(l) + KCl(aq) ΔHneut (10.2)

1) According to Hess's law, the total change in enthalpy of a reaction resulting from differents changes in various reactions can be calculated as the sum of all the enthalpies of all those reactions.

Hence, to get reaction 10.3:

KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)

We need to add reaction 10.2 to the reverse of reaction 10.1

KOH(s) + HCl(aq) + KOH(aq) → H₂O(l) + KCl(aq) + KOH(s)

Canceling the KOH(s) from both sides, we get reaction 10.3:

KOH(aq) + HCl(aq) → H₂O(l) + KCl(aq) (10.3)

2) The change in enthalpy for reaction 10.3 can be calculated as the sum of the enthalpies ΔHsoln and ΔHneut:

$\Delta H = \Delta H_{soln} + \Delta H_{neut}$