How is counting a truckload of pennies like counting the atoms in 10.0 g of aluminum? How is it different?
1 answer:
Answer:
Explanation:
A truckload of pennies is quite a very large amount of problem to solve. A truck can carry a lot of coins which can be up to several millions in number approximately.
This is similar to counting the number of atoms in 10.0g of aluminium.
In a mole of any substance, there are 6.02 x 10²³ atoms.
number of moles =
molar mass of Al = 27g/mole
number of moles = = 0.37moles
Number of atoms = 0.37 x 6.02 x 10²³ = 2.23 x 10²³ atoms
In 10g of aluminium, there are 2.23 x 10²³ atoms. It is even much more tedious to count.
Difference;
We can see the pennies in the truckload. They are discrete. It is impossible to see atoms in a substance this way.
Also, the number of atoms in 10g of aluminium is more than that of pennies in a truckload.
You might be interested in
The compounds can react with OH⁻ and HCO₃⁻ only C₅H₆N pyridinium
<h3><em>Further explanation </em></h3>In an acid-base reaction, it can be determined whether or not a reaction occurs by knowing the value of pKa or Ka from acid and conjugate acid (acid from the reaction)
Acids and bases according to Bronsted-Lowry
Acid = donor (donor) proton (H + ion)
Base = proton (receiver) acceptor (H + ion)
If the acid gives (H +), then the remaining acid is a conjugate base because it accepts protons. Conversely, if a base receives (H +), then the base formed can release protons and is called the conjugate acid from the original base.
From this, it can be seen whether the acid in the product can give its proton to a base (or acid which has a lower Ka value) so that the reaction can go to the right to produce the product.
The step that needs to be done is to know the pKa value of the two acids (one on the left side and one on the right side of the arrow), then just determine the value of the equilibrium constant
Can be formulated:
K acid-base reaction = Ka acid on the left : K acid on the right.
or:
pK = acid pKa on the left - pKa acid on the right
K = equilibrium constant for acid-base reactions
pK = -log K;
K value> 1 indicates the reaction can take place, or the position of equilibrium to the right.
There is some data that we need to complete from the problem above, which is the pKa value of some compounds that will react, namely:
pyridinium pKa = 5.25
acetone pKa = 19.3
butan-2-one pKa = 19
Let's look at the K value of each possible reaction:
pka H₂O = 15.74, pka of H₂CO₃ = 6.37)
- 1. C₅H₆N pyridinium
* with OH⁻
C₅H₆N + OH- ---> C₅H₅N- + H₂O
pK = pKa pyridinium - pKa H₂O
pK = 5.25 - 15.74
pK = -10.49
K values> 1 indicate the reaction can take place
* with HCO3⁻
C₅H₆N + HCO₃⁻-- ---> C₅H₅N⁻ + H₂CO₃
pK = 5.25 - 6.37
pK = -1.12
Reaction can take place
- 2. Acetone C₃H₆O
* with OH-
C₃H₆O + OH⁻ ---> C₃H₅O- + H₂O
pK = 19.3 - 15.74
pK = 3.56
Reaction does not happen
* with HCO₃-
C₃H₆O + HCO₃⁻ ----> C₃H₅O⁻ + H₂CO₃
pK = 19.3 - 6.37
pK = 12.93
Reaction does not happen
- 3. butan-2-one C₄H₇O
* with OH-
C₄H₇O + OH- ---> C₄H₆O- + H₂O
pK = 19 - 15.74
pK = 3.26
Reaction does not happen
* with HCO₃⁻
C₄H₇O + HCO₃⁻ ---> C₄H₆O⁻ + H₂CO₃
pK = 19 - 6.37
pK = 12.63
Reaction does not happen
So that can react with OH⁻ and HCO₃⁻ only C₅H₆N pyridinium
<h3><em>Learn more </em></h3>
the lowest ph
the concentrations at equilibrium.
the ph of a solution
Keywords : acid base reaction, the equilibrium constant
