How many grams of potassium sulfite are required to dissolve in 872g of water to make a 0.128m solution?

Answer 1

#"17.7 g"#

You're looking for the mass of potassium sulfite, #"K"_2"SO"_3"#, needed to make a #"0.128 m"#, or #"0.128 molal"#, solution.

Now, molality is used to express the concentration of a solution in terms of how many moles of solute it contains per kilogram of solvent.

This means that in order to find a solution's molality, you need to know

In your case, you already know the mass of the solvent in grams, so the very first thing to do here is convert it to kilograms

#872 color(red)(cancel(color(black)("g"))) * "1 kg"/(10^3color(red)(cancel(color(black)("g")))) = "0.872 kg"#
Now, a #"0.128 m"# solution contains #0.128# moles of solute per kilogram of solvent. Since your sample contains #"0.872 kg"# of solvent, it follows that it will contain
#0.872 color(red)(cancel(color(black)("kg solvent"))) * overbrace(("0.128 moles K"_2"SO"_3)/(1color(red)(cancel(color(black)("kg solvent")))))^(color(blue)("= 0.128 m")) = "0.1116 moles K"_2"SO"_3#

All you have to do now is use the molar mass of potassium sulfite to figure out how many grams would contain that many moles

#0.1116 color(red)(cancel(color(black)("moles K"_2"SO"_3))) * "158.26 g"/(1color(red)(cancel(color(black)("mole K"_2"SO"_3)))) = color(green)(|bar(ul(color(white)(a/a)color(black)("17.7 g")color(white)(a/a)|)))#

The answer is rounded to three sig figs.

Sign up to view the whole answer

By signing up, you agree to our Terms of Service and Privacy Policy

Sign up with email
Answer 2

To make a 0.128 M solution, you would need 6.05 grams of potassium sulfite to dissolve in 872 grams of water.

Sign up to view the whole answer

By signing up, you agree to our Terms of Service and Privacy Policy

Sign up with email
Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.

Not the question you need?

Drag image here or click to upload

Or press Ctrl + V to paste
Answer Background
HIX Tutor
Solve ANY homework problem with a smart AI
  • 98% accuracy study help
  • Covers math, physics, chemistry, biology, and more
  • Step-by-step, in-depth guides
  • Readily available 24/7