[laurel2697]

Here is the question that I have been working all day on and if someone can show me what I am doing wrong I would be very grateful. Thanks!!

If you mix 25.0ml of 0.50M K2CO3 (Potassium Carbonate, sorry I do not know how to use the sub buttons yet) with 15.0ml of 0.30M MgCl2 (Magnesium Chloride) what is your limiting reagent?

I have done both of these and they both are limiting reagents, one just more of a limiting reagent (K2CO3)

Here is what I have formulated:

25.0 ml / 1000ml × 138.21 mol × 0.50M = 1.7M K2CO3 Needed and I Have 0.50M of K2CO3, therefor K2CO3 is my limiting reagent.

Am I on the right track here?

[laurel2697]

Somebody Please help me with this. I have been working on this all day. I also have formulated it other ways. I know how to do limiting reagents, but I have not been shown how to do this type in class. This is part of a homework assignment and after this question it asks for the theoretical yield and the percent yield so I can not move on until I figure this question out. 

[Borek]

they both are limiting reagents, one just more of a limiting reagent (K2CO3)

There is always one limiting reagent, the other one is in excess.

25.0 ml / 1000ml × 138.21 mol × 0.50M = 1.7M K2CO3 Needed and I Have 0.50M of K2CO3, therefor K2CO3 is my limiting reagent.

No idea what you are doing - what is 138.21 mol?

You should start with a reaction equation and calculation of amounts of both reactants. Do you know how to read the reaction equation?

[laurel2697]

Thank you for your response. Please bare with me. Chemistry is very new to me but I am loving it. Looks like I did not post the question right and its entirety. I am trying to find the limiting reagent in a balanced chemical reaction. Here is the balanced equation:

K₂CO₃+MgCl₂ :rarrow:2KCl+MgCO₃

Here is the question again:
If you mix 25.0ml of 0.50M K₂CO₃ with 15.0ml of 0.30M MgCl₂ what is your limiting reagent?

I figured out that I need to find how many mols in each based on the info given:
25.0ml K2Co3 / 1000ml K2CO3 x 0.50ml K2CO3 = 0.025 mol K2CO3 that I HAVE
15.0ml MgCl2 / 1000ml MgCl2 x 0.30ml MgCl2   = 0.0045 mol MgCl2 that I HAVE

I know that I now need to figure out how many mols of each that I NEED. Starting with the mols K2CO3 I am trying to get to the mols of MgCl2 using the balance equation above. This is where I am getting tripped up. 

[Borek]

They react 1:1, so you need 1 mole of the other for the reaction of 1 mole of the substance.

How many moles of K₂CO₃ would you need for reaction with MgCl₂? Do you have that much?

How many moles of MgCl₂ would you need for reaction with K₂CO₃? Do you have that much?

If you don't have enough, its your limiting reagent.

[laurel2697]

Thank you Borak for taking the time to help me. I got it. Thanks again, you really saved me.