[John11]

You are given a sample that contains a mixture of the following two arsenic-containing minerals: paakkonenite (Sb2AsS2) and orpiment (As2S3). You start with a sample of this mixture that has a mass of 98.49 grams. You perform a reaction that converts the arsenic (As) in these minerals into the form calcium arsenate (Ca3(AsO4)2), and 62.46 grams of this product are obtained.
What is the percent by mass of paakkonenite in the original sample?

I don't understand the steps that need to be taken in order to solve this problem. Any help or clarity is appreciated.

[Borek]

Please read the forum rules. You have to show your attempts at answering the question/solving the problem to receive help, it is a forum policy.

Hint: you have two unknowns: mass of paakkonenite and orpiment. Information given allows you to write two equations.

[Orcio_87]

@John11

I would start with writing two equations.

1. how much Ca₃(AsO₄)₂ I will get from 98,49 g of Sb₂AsS₂ + how much Ca₃(AsO₄)₂ I will get from 98,49 g of As₂S₃.

2. mixture cointains only Sb₂AsS₂ and As₂S₃ (they give 100 % in all).