determing caco3 contents (Revised)

[donola]

To start i am a chemistry novice as such looking for help.

 

I have a sample of building rendor, and need determine the lime content of the example.

My theory (spot the flaws please), is to:

(1)crush the sample into powder form

(2) add a diluted Hydrochloric acid,

(3)heat to drive off co2

(4)add water inorder to filter(to filter off aggregates from the building rendor, eg sands, stones etc)

 

*note making weight measurements after all procedures

 

My theory is that the lime will be broken down into its salts, which will be soluble in water, so i will be left with a solution of water and calcuim , magnesium, silca salts etc(lime).

 

My questions are: Is this a flawed theory

If not, could i use a crude filtering sysem eg Coffee filter

 

*note , i do have a tolerence in the results i am looking for a resonable idea of the make up the material

 

thks, please do not laugh at my basic knowledge

 

thks

[YT2095]

a coffee filter will work just fine.

use excess HCl also.

when the reaction is complete, you can rinse that which remains in your filter paper with pure water and then dry this insoluble mass.

then weigh it.

subtract that from the starting weight, and the difference will be mostly the calcium content.

if it`s ONLY the carbonate form that you need to know, they you`ll have to measure the quantity of the gas (CO2) evolved during the reaction.

use a Gas Syringe for this.

[donola]

i have noticed a mistake in my previous thread, that i would like to clear up to sace confusion

 

I wrote CACO3 , when i actually meant CACO, hence the burning off the CO2

 

Sorry to confuse

 

Thx Donola , the novice

[YT2095]

the only problem there is that CaCO doesn`t exist in any ref I know of

[donola]

I meant CAO calcuim oxide

 

Thxs for ur help, the tips were very useful, and have proved successful enough for me to identify the compsites i require

 

Thanks alot

[YT2095]

no problems, I was beginning to wonder what you`de be doing with Carbonyls of calcium Ca^2+(CO)3

 

the oxide will quickly react to make Carbonate and hydroxide if left in the air for any length of time, your product after reaction will be Calcium Chloride, you could evaporate this to crystals and examine them as further proof of the calcium presence also.

as you stated though, it Will have other impurities such as magnessium and Iron in it also.