Why can liquids change shape but solids cannot

In the first step of hydroboration mechanism, why is an arrow drawn from the pi bond of the alkene to the B atom of the borane r

fomenos

Answer:

To fulfill octet of B atom in borane, nucleophilic attack by pi electrons of alkene takes place with electrophilic B center in borane.

Explanation:

In Borane ( $BH_{3}$ ), B atom has energetically vacant 2p orbital and thereby octet is incomplete.Therefore B center in borane act as an electrophilic center.

In alkene, pi bonding electrons are loosely bound together due to side on overlap of two constituent p-orbitals. Hence this pi bond can be easily broken. Alternatively, we can say that pi bond in alkene act as a potential nucleophile.

The first step of hydroboration occurs in a concerted manner where pi electrons of alkene first attack vacant 2p orbital of B in borane to fulfill it's octet (represented by an arrow drawn from alkene to B atom) and forms a 4 memebered cyclic intermediate. Simulaneously, a B-H bond in borane is donated to alkene through 3c-2e bond (3 center-2 electron bond).

Full mechanism has been shown below.

5 0

3 years ago

ANSWER PLS GIVING BRAINLIEST TO WHO ANSWERS CORRECTLY

ale4655 [162]

Answer:

Supergiant

Explanation:

3 0

3 years ago

Read 2 more answers

What is the molarity of each ion in a solution prepared by dissolving 0.520 g of na2so4, 1.186 g of na3po4, and 0.223 g of li2so

Leto [7]

First calculate the number of moles of each ion present
for Na2So4 is
0.52/142=0.0037moles
Na+ =0.0037 x2 =0.0074moles
SO4^-2 =0.0027moes

for Na3PO4= 1.186/164=0.0072 moles
Na+ =0.0072 x3=0.0216moles
po4 ions = 0.0072 moles

for LiSo4 =0.223/110=0.002moles
Li ions=0.002 x2 =0.004mole
SO4 ions =0.002moles
total moles for
Na ions =0.0216 +0.0074 =0.029moles
forSO4 ions =0.0037 +0.002=0.0057moles
molarity is therefore
Na ion=0.029/0.1=0.29M
SO4 ions=0.0057/0.1=0.057M
Li ions =0.004/0.1=0.04M
PO4 ions=0.0072/0.1=0.072M

8 0

3 years ago

How many moles of Kr are contained in 398 mg of Kr?

bagirrra123 [75]

The mass of 1 mole of an element is its atomic weight on the Periodic Table in grams.

1g = 1000mg

The mass of 1 mole of Kr = 83.80g Kr

Convert mg Kr to g Kr.

398mg Kr x (1g/1000mg) = 0.398g Kr

Convert g Kr to mol Kr.

0.398g Kr x (1mol Kr/83.80g Kr) = 4.75x10-3mol Kr

8 0

3 years ago

1. What is the rate law and the value of the rate constant for the reaction: 2 AB2 + C -- CB What is the order for each reactan

Brut [27]

Answer :

The rate law becomes:

$\text{Rate}=k[AB_2]^2[C]^2$

The value of the rate constant 'k' for this reaction is $1.4\times 10^{-7}M^{-3}min^{-1}$

The order of each reactant is, 2

Overall order of reaction = 4

Explanation :

Rate law is defined as the expression which expresses the rate of the reaction in terms of molar concentration of the reactants with each term raised to the power their stoichiometric coefficient of that reactant in the balanced chemical equation.

For the given chemical equation:

$2AB_2+C\rightarrow CB$