The unknowns are a mixture of ferrous ammonium sulfate and ammonium sulfate. calculate the amount of ferrous ammonium sulfate and the amount of ammonium sulfate needed to prepare a sample that is 10% fe with a total mass of 0.2 g

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Molar mass of ferrous ammonium sulfate =392 g / mol

Mass of iron present in ferrous ammonium sulfate = 56 g/mol

Total mass required = 0.2 g

Total mass of iron Fe required = 10% of 0.2 g

                                           = x0.2

                                            = 0.02 g

Only ferrous ammonium sulfate has iron. So all iron must be present only as ferrous ammonium sulfate.

56 g of iron is present in 392 g of ferrous ammonium sulfate

0.02 g of iron is present in x 0.02

                                                       = 0.14 g

Mass of ammonium sulfate = 0.2 - 0.14 = 0.06 g

Thus the required composition must be 0.06 g ammonium sulfate and 0.14 g ferrous ammonium sulfate.

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles

answer

fusion: the energy source of stars. the energy released from the collapse of the gas into a protostar causes the center of the protostar to become extremely hot. when the core is hot enough, nuclear fusion commences. fusion is the process where two hydrogen atoms combine to form a helium atom, releasing energy.

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