You would know that the variable is quantitative if it shows any number to express the quantity. For example, quantitative variables are 50°C, 5 atm, 2 moles, 100 L and so on. A variable is qualitative if it expresses a relative quantity but not expressing a number. Examples would be: few, too hot, several, or even describing the characteristics of a variable. Hence, when the variable is in grams, then that would be quantitative.
Answer:
0.161moles
Explanation:
Given parameters:
Mass of Fe = 18g
Oxygen gas is in excess
Unknown:
Number of moles of Fe₂O₃ produced = ?
Solution:
To start with, let us write a chemically balanced equation before proceeding to understand the nuances of this problem.
4Fe + 3O₂ → 2Fe₂O₃
In the equation above above, 4 mole of iron combined with 3 moles of oxygen gas to 2 moles of Fe₂O₃.
In solving this problem, we can identify that Fe is the limiting reactant since we have been told oxygen gas is in excess. The suggests that the extent to which the product is formed and the reaction proceeds hinges on the amount of Fe we have.
It is best to work from the given, or known reactant to the unknown
The known in this scenario is the mass of Fe. Let us find the number of moles of this specie;
Number of moles of Fe = 
Molar mass of Fe = 56g/mol
Number of moles =
= 0.32mol
Using this known number of moles of Fe, we can relate it to that of the unknown amount of the product and obtain the number of moles.
4 moles of Fe produced 2 moles of Fe₂O₃
0.32 moles of Fe will produce
= 0.161moles
Answer:
1= K⁺= (Z=19) = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰
2 = Zn²⁺= (Z = 30) =1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰, 3d¹⁰
Explanation:
When an atom lose or gain the electron ions are formed. There are two types of ions cation and anion.
Cation are formed when atom lose the electron.
Anion are formed when an atom gain the electron.
In given question potassium loses its valance electron and form K⁺ cation. Thus its electronic configuration will be written as,
₁₉K⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰
While the electronic configuration of potassium in neutral form is:
₁₉K = 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹
The atomic number of zinc is 30 and its electronic configuration is:
₃₀Zn= 1s² 2s² 2p⁶ 3s² 3p⁶ 4s², 3d¹⁰
When zinc atom loses its 2 valance electrons the electron configuration will be,
₃₀Zn²⁺= 1s² 2s² 2p⁶ 3s² 3p⁶ 4s⁰, 3d¹⁰
If you search the question text (starting with "Write") you will definitely find the answer