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lord [1]
3 years ago
6

A sample of pure calcium fluoride with a mass of 15.0 g contains 7.70 g of calcium. how much calcium is contained in 45.0 g of c

alcium fluoride?
Chemistry
1 answer:
kolbaska11 [484]3 years ago
6 0

In a sample of pure calcium fluoride of mass 15.0 g, 7.70 g of calcium is present. First convert the mass into number of moles as follows:

n=\frac{m}{M}

Here, m is mass and M is molar mass.

Molar mass of Ca is 40 g/mol, putting the values,

n=\frac{7.70 g}{40 g/mol}=0.1925 mol

Similarly, molar mass of CaF_{2} is 78.07 g/mol thus, number of moles will be:

n=\frac{15.0 g}{78.07 g/mol}=0.1921 mol.

Thus, 0.1921 mol of CaF_{2} have 0.1925 mol of Ca, or 1 mole of CaF_{2} will have approximately 1 mole of Ca.

Now, mass of Ca needs to be calculated in 45.0 g of CaF_{2}. Converting mass into number of moles first,

n=\frac{45.0 g}{78.07 g/mol}=0.5764 mol

Thus, number of moles of Ca will also be 0.5764 mol, converting number of moles into mass,

m=n\times M=0.5764 mol\times 40 g/mol=23.06 g

Therefore, mass of Ca will be 23.06 g.

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The atomic symbol Superscript 206 subscript 82 upper P b. represents lead-206 (Pb-206), an isotope that has 82 protons and 124 n
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\left \{ {{y=206} \atop {x=82}}Pb \right.

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isotopes are various forms of same elements with different atomic number but different mass number.

Radioactivity is the emission of rays or particles from an atom to produce a new nuclei. There are various forms of radioactive emissions which are

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in the problem the product formed after radiation was Pb-206. isotopes of lead include Pb-204, Pb-206, Pb-207, Pb-208. they all have atomic number 82. which means the radiation cannot be ∝ or β since both radiations will alter the atomic number of the parent nucleus.

Only gamma radiation with \left \{ {{y=0} \atop {x=0}}γ \right. will produce a Pb-206 of atomic number 82 and mass number 206 , since gamma ray have 0 mass and has 0 atomic number.equation is shown below

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The answer is- SF_{6} is octahedral in electronic and molecular geometry with 6 Fluorine atoms bonded to central atom S.

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