Answer:
Niels Bohr, refined the model of an atom by proposing a quantized shell structure atomic model in order to describe how the electrons are able to maintain stable orbits around the nucleus
Based on the predictions of classical mechanics the electron motion of the Rutherford model was unstable as the electrons where expected to have lost some energy during motion and thus having to come rest in the nucleus
According to the modification by Neils Bohr in 1913, electrons move in shells or orbits of fixed energy and emission of electromagnetic radiation takes place only when electrons changes the orbit in which they move
Explanation:
Answer:
27.6mL of LiOH 0.250M
Explanation:
The reaction of lithium hydroxide (LiOH) with chlorous acid (HClO₂) is:
LiOH + HClO₂ → LiClO₂ + H₂O
<em>That means, 1 mole of hydroxide reacts per mole of acid</em>
Moles of 20.0 mL = 0.0200L of 0.345M chlorous acid are:
0.0200L ₓ (0.345mol / L) = <em>6.90x10⁻³ moles of HClO₂</em>
To neutralize this acid, you need to add the same number of moles of LiOH, that is 6.90x10⁻³ moles. As the LiOH contains 0.250 moles / L:
6.90x10⁻³ moles ₓ (1L / 0.250mol) = 0.0276L of LiOH =
<h3>27.6mL of LiOH 0.250M</h3>
Answer:
Rb+
Explanation:
Since they are telling us that the equivalence point was reached after 17.0 mL of 2.5 M HCl were added , we can calculate the number of moles of HCl which neutralized our unknown hydroxide.
Now all the choices for the metal cation are monovalent, therefore the general formula for our unknown is XOH and we know the reaction is 1 equivalent acid to 1 equivalent base. Thus we have the number of moles, n, of XOH and from the relation n = M/MW we can calculate the molecular weight of XOH.
Thus our calculations are:
V = 17.0 mL x 1 L / 1000 mL = 0.017 L
2.5 M HCl x 0.017 L = 2.5 mol/ L x 0.017 L = 0.0425 mol
0.0425 mol = 4.36 g/ MW XOH
MW of XOH = (atomic weight of X + 16 + 1)
so solving the above equation we get:
0.0425 = 4.36 / (X + 17 )
0.7225 +0.0425X = 4.36
0.0425X = 4.36 -0.7225 = 3.6375
X = 3.6375/0.0425 = 85.59
The unknown alkali is Rb which has an atomic weight of 85.47 g/mol
- Calcium carbonate is the salt among the given options.
- Calcium carbonate ( CaCO3) can be regarded as which appears as white and odorless powder or as a colorless crystals it is insoluble in water.
- The chemical formula is CaCO3. It can be used as an antacid as well as food colouring and a food firming agent and a fertilizer.
- Calcium carbonate is calcium salt as well as carbonate salt with one-carbon compound
- Salt can be regarded as substance which is produced by reaction between acid and base. It consists negative ion (anion) of that acid as well as positive ion (cation) of the base.
- Sodium hydroxide is a base and not a salt
- Carbonic acid is an acid and not a salt
- Therefore, calcium carbonate is the only salt in the among the given options.
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Answer:
24m/s
Explanation:
a=change of v/change of t
6m/s^2=v/4s
multiply both sides by 4s
v=24m/s
