## Fundamentals G21

Tianjian Lai 2K
Posts: 36
Joined: Wed Sep 30, 2020 9:38 pm

### Fundamentals G21

Hi everyone,

G21 asks us to find the molarity of potassium and sulfide ions in a solution is prepared by dissolving 0.500 g of KCl, 0.500 g of K2S, and 0.500 g of K3PO4 in 500 mL of water.

I know the molarity equation is (moles of solute) / (volume of solution).

For this problem, shouldn't the volume of the solution be 500mL water + volume(0.500 g KCl) + volume(0.500 g K2S) + volume(0.500 g K3PO4)? But are we able to calculate the volume of KCl, K2S, and K3PO4 given the info we have? Or should we assume that 1.5 g of solute is negligible for the total volume of the solution?

VSU_2G
Posts: 47
Joined: Wed Sep 30, 2020 10:03 pm
Been upvoted: 1 time

### Re: Fundamentals G21

In this case, the grams of solute don't contribute to the overall volume, so it's negligible. Therefore, 500 mL is the total volume of this solution.

Rachel Jiang 2G
Posts: 37
Joined: Wed Sep 30, 2020 9:58 pm
Been upvoted: 1 time

### Re: Fundamentals G21

Yes, I agree that the mass of solutes is negligible since they are really small so you should just use 500 mL as the volume of solution.

Alessia Renna 1D
Posts: 36
Joined: Wed Sep 30, 2020 9:36 pm

### Re: Fundamentals G21

The volume would be the 500 mL of water, usually volume in dilution equations will be in L or mL