Answer:
1) Ca: [Ar]4s²
2) Pm: [Xe]6s²4f⁵
Explanation:
1) Ca:
Its atomic number is 20. So it has 20 protons and 20 electrons.
Since it is in the row (period) 4 the noble gas before it is Ar, and the electron configuration is that of Argon whose atomic number is 18.
So, you have two more electrons (20 - 18 = 2) to distribute.
Those two electrons go the the orbital 4s.
Finally, the electron configuration is [Ar] 4s².
2) Pm
The atomic number of Pm is 61, so it has 61 protons and 61 electrons.
Pm is in the row (period) 6. So, the noble gas before Pm is Xe.
The atomic number of Xe is 54.
Therefore, you have to distribute 61 - 54 = 7 electrons on the orbitals 6s and 4f.
The resultant distribution for Pm is: [Xe]6s² 4f⁵.
The kind of reaction that occurs when you mix aqueous solutions of barium sulfide and sulfuric acid is a precipitation reaction.
<h3>Further Explanation</h3>
- The chemical reaction between Ba(OH)2(aq) and H2SO4(aq) is given by;
Ba(OH)₂(aq) + H₂SO4(aq) --> BaSO₄(aq) + 2H₂O(l)
- This is a type of precipitation reaction, where a precipitate is formed after the reaction, that is Barium sulfate.
<h3>Other types of reaction</h3><h3>Neutralization reactions </h3>
- These are reactions that involve reacting acids and bases or alkali to form salt and water as the only products.
- For example a reaction between sodium hydroxide and sulfuric acid.
NaOH(aq) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l)
<h3>Displacement reactions</h3>
- These are reactions in which a more reactive atom or ion displaces a less reactive ion from its salt.
Mg(s) + CuSO₄(aq) → MgSO₄(aq) + Cu(s)
<h3>Redox reactions </h3>
- These are reactions that involve both reduction and oxidation occuring simultaneously durin a chemical reaction.
- For example,
Mg(s) + CuSO₄(aq) → MgSO₄(aq) + Cu(s)
- Magnesium atom undergoes oxidation while copper ions undergoes reduction.
<h3>Decomposition reactions</h3>
- These are type of reactions that involves breakdown of a compound into its constituents elements.
- For example decomposition of lead nitrate.
Pb(NO3)2(S) → PbO(s) + O2(g) + NO2(g)
Keywords: Precipitation
<h3>Learn more about: </h3>
Level: High school
Subject: Chemistry
Topic: Chemical reactions
Sub-topic: Precipitation reactions
Pipes are made of the element Lead so the answer should be d) lead pipe
Answer:
87.15%
Explanation:
To find percent yield, we can use this simple equation
Where "Actual" is the amount in grams actually collected from the reaction, and "Theoretical" is, well, the theoretical amount that should have been produced.
They give us these values, so to find the percent yield, just plug the numbers in.
So, the percent yield is 87.15%
An easy trick to remember how to do this is just to divide the smaller number by the bigger number and move the decimal back two places. If you have a percent yield greater than 100%, something is wrong in the reaction.
