<u>Answer:</u> The number of moles of calcium metal required is 2.0 moles.
<u>Explanation:</u>
We are given:
Moles of water reacted = 4.0 moles
The given chemical reaction follows:

By Stoichiometry of the reaction:
2 moles of water is reacted with 1 mole of calcium metal
So, 4.0 moles of water will react with =
of calcium metal
Hence, the number of moles of calcium metal required is 2.0 moles.
Answer:
The answer to your question is MgSO₄ 5H₂O
Explanation:
Data
mass of MgSO₄ = 2.86 g
mass of H₂O = 2.14 g (5 - 2.86)
Process
1.- Calculate the molecular mass of the compounds
MgSO₄ = 24 + 32 + (16 x 4) = 120
H₂O = 16 + 2 = 18
2.- Convert the grams obtain to moles
120 g of MgSO₄ --------------- 1 mol
2.8 g ---------------- x
x = (2.8 x 1)/120
x = 0.024 moles
18 g of H₂O --------------------- 1 mol
2.14 g -------------------- x
x = (2.14 x 1)/18
x = 0.119
3.- Divide by the lowest number of moles
MgSO₄ = 0.024/0.024 = 1
H₂O = 0.119/ 0.024 = 5
4.- Write the molecular formula
MgSO₄5H₂O
In a polyatomic ion, the ate ending indicates one more oxygen than the ite ending. D. more.
i don't know but try putting this diagram into a question on google. you should be able to get some type of answer if not the right answer. good luck and * hint* you can make a really good question out of the sentence on top of the DIAGRAM. I hope this was helpful. please let me know in the comments: )