Answer:
This question is incomplete because of the absence of the molecules been referred to in the question. However, the molecules been referred to in the question is in the attachment below
Explanation:
First of all, we have to define lewis acid and lewis base.
A lewis acid is a substance that has the capacity to accept a pair of electrons. For example, H⁺. While a lewis base is a substance that is capable of donating a pair of electrons (to a lewis acid). For example, OH⁻.
Going by the definitions above, we can deduce the type of substance the molecules in the question (attachment) are
a. BF₃ (boron trifluoride) is a lewis acid because the central atom (as suggested to be focused on in the question) which is <u>boron, has the capacity to accept a pair of electrons</u>.
b. The central atom (carbon) in the compound (2-methyl propane) <u>also has the capacity to accept a pair of electrons</u> since it is positively charged (is electron deficient). Hence, it is a lewis acid.
c. The functional group in this compound (trimethyl borate) is the ether. Ethers are generally lewis bases because the oxygen atom in an ether can donate a pair of electrons from it's lone pair. However, the <u>presence of boron which is central to the compound</u> shows it is also a lewis acid, although weak (majorly due to the presence of the ethers).
Answer:
K = 2.7x10⁻⁵ at 25ºC
Explanation:
A way to write Arrhenius equation is:
ln K = - Ea/R × (1/T) + lnA
If you graph ln K as Y and 1/T as X (Absolute temperature in K), the equation you will obtain is:
Y = -13815X +35.817
R² = 0.9927
(Taking the last k point as 0.0386) (ln 0.0386), <em>0.1386 has no sense</em>)
Your slope is -13815
-13815K = - Ea/R
-13815K×8.314J/molK = 114858J/mol = Ea
And your intercept =
lnA = 35.817
A = 3.59x10¹⁵
Now, you want to know rate constant at 25ºC = 298.15K. Replacing in the equation (Where Y is ln (activation energy) and X is 1/T):
Y = -13815X +35.817
Y = -13815(1/298.15K) +35.817
Y = -10.5187
lnK = -10.5187
<h3>K = 2.7x10⁻⁵ at 25ºC</h3>
Answer:
element made up of four (4) similar atoms.
Explanation:
An element is made up of one kind of atom. A compound is made up of 2 or more different kinds of atoms that are chemically together.
Answer:
The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
Explanation:
Where:
Q = heat absorbed or heat lost
c = specific heat of substance
m = Mass of the substance
ΔT = change in temperature of the substance
We have mass of copper = m = 25.3 g
Specific heat of copper = c = 0.385 J/g°C
ΔT = 39°C - 22°C = 17°C
Heat absorbed by the copper :
The heat needed to warm 25.3 g of copper from 22°C to 39°C is 165.59 Joules.
<h3>Solution-:</h3>
- option D
- maintains a constant volume.
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