Answer:
B and D as well
Explanation:
All the electronic configuration of the elements of B end on s sub shell.
S energy level sub shell can hold 2 electrons and since Be, Mg, Ca Sr end in s.
We can say, they have same valence electrons, i.e 2 electrons.
Answer:
115g/mol
Explanation:
To get the molar mass, we know that the it is equal to the mass divided by the number of moles. We have the mass but we do not have the number of moles.
We get this by working through the solution information. Firstly, we need to know the number of moles in 750ml for a molarity of 0.29m
Now, since 0.29 moles is present in 1000ml, x moles will be present in 750ml
The value of x is obtained as follows:
x = (750 * 0.29)/1000 = 0.2175 moles
Now since we have the number of moles, we can then obtain the molar mass.
Molar mass = mass/number of moles = 25.0g/0.2175 = 114.94 approximately 105g/mol
Answer:
<h2>
<u>W</u><u>ater</u> covers 70 percent of earth's surface.</h2>
The mass (in grams) of iron, Fe that can be made from 21.5 g of Fe₂O₃ is 15.04 g
We'll begin by writing the balanced equation for the reaction. This is given below:
2Fe₂O₃ -> 4Fe + 3O₂
- Molar mass of Fe₂O₃ = 159.7 g/mol
- Mass of Fe₂O₃ from the balanced equation = 2 × 159.7 = 319.4 g
- Molar mass of Fe = 55.85 g/mol
- Mass of Fe from the balanced equation = 4 × 55.85 = 223.4 g
From the balanced equation above,
319.4 g of Fe₂O₃ decomposed to produce 223.4 g of Fe
<h3>How to determine the mass of iron, Fe produced</h3>
From the balanced equation above,
319.4 g of Fe₂O₃ decomposed to produce 223.4 g of Fe
Therefore,
21.5 g of Fe₂O₃ will decompose to produce = (21.5 × 223.4) / 319.4 = 15.04 g of Fe
Thus, 15.04 g of Fe were produced.
Learn more about stoichiometry:
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