preparation of elemental phosphorus can be done as follows:
2Ca3(PO4)2 + 6SiO2 --> 6CaSiO3 + P4O10
P4O10 + 10C --> P4 + 10CO
calculate the % of Ca3(PO4)2 initially present in the sample if 307kg of phosphate rock yields 42.5kg of elemental P4
First, you have to ensure that the equations are balanced. It seems that both of the equations are balanced. Next, you can combine the two equations to form a single equation to show the relationship of the compounds. By doing so, you will have the chemical equation:
`2Ca_3(PO_4)_2 + 6SiO_2 + 10 C -> 6CaSiO_3 + P_4O_10 + P_4 + 10 CO`
Next, we do some stoichiometric procedure for the determination of the mass of `Ca_3(PO_4)_2` and eventually the percent mass of it in the sample.
`= 212, 802.001 grams of Ca_3(PO_4)_2`
`= 212.80 kg of Ca_3(PO_4)_2`
To calculate the percent `Ca_3(PO_4)_2` in the sample, we divide it by the total amount of sample multiplied by 100.
`% Ca_3(PO_4)_2 = (Mass Ca_3(PO_4)_2)/(mass of sampl e) * 100`
` ` `% Ca_3(PO_4)_2= (212.80 kg)/(307 kg) * 100`
`% Ca_3(PO_4)_2 = 69.3%` --> final answer