Please help me with the following problems.(adsbygoogle = window.adsbygoogle || []).push({});

1.)(85) A 55-g sample of a geseous fuel mixture contains 0.51 fraction propane C3H8; the remainder is butane. What are masses of propane and butane in sample?

Using the formula: Ax = n(solute)/n(total), i initially solved for total moles. I went about this by multiplying 7 by the molar mass of carbon (there is a total of 7 carbons) and similarly, 18 by the molar mass of hydrogen. This allows me to solve for moles of solute, which i then convert into mass. However, i get an answer of 12.1g and 43.0 g, which differs from the book.

2.) (105) A solution has 0.375 mol Na2CO3, 0.125 mol Ca(NO3)2, and 0.200 mol AgNO3 in 2.0 L of water. Write balanced reactions and calculate molarities of each ion.

I noticed that NO3(-1) is always soluble. CO3(2-) can form solids with Ca+ and Ag+. So i wrote two seperate reactions, one in which CaCO3 was the solid, and the other in which Ag2CO3 was the solid. This allowed me to get the moles of Na+, which i then converted into molarity. But I'm not sure this is the correct way of approaching this question.

Thank you.

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: General Chemistry Questions (Solubility)

**Physics Forums | Science Articles, Homework Help, Discussion**