[billionzz]

if I heat up sodium bicarbonate to 400 degrees F for and hour in theory it should change to sodium carbonate.

Can someone tell me how to calculate how much sodium carbonate it would take to make 5 liters of di water have a KH (carbonate hardness) of 50dKH?

Thanks for your help,
Bill

[AWK]

Hard water contains Ca²⁺ and Mg₂₊ salts, not Na₂CO₃
What does mean "dKH" - German degree of hardness?

[billionzz]

I would be using deionized water.

Yes, dKH is German degrees of hardness.

Thanks for your help,
Bill

[DevaDevil]

k, after searching I found:

1dKH = 10.7145 ppm CO₃^2- = 10.7145 mg CO₃^2- /l

so 50 = 53.57 mg carbonate needed per liter

now, just transform it to 5 litre, then calc to moles

[billionzz]

I promise that I'm not trying to be lazy but I really don't know how to apply the information you gave me.

Is it possible for you to make it into a formula for me?

Thanks for your help, I appreciate it,
Bill

[billionzz]

>>>, after searching I found:

1dKH = 10.7145 ppm CO32- = 10.7145 mg CO32- /l

so 50 = 53.57 mg carbonate needed per liter

now, just transform it to 5 litre, then calc to moles
<<<

Let me see if I understand, if I add 53.57 mg of sodium carbonate to 1 liter of distilled water that will give me a dKH of 50.

You said just to transform that to 5 liters and calc to moles.

Could you please explain the calculate to moles I don't know what that means? Wouldn't it just be 53.57 mg x 5 for 5 liters of water.

I saw two different forms of sodium carbonate for sale, Sodium Carbonate Monhydrate and Sodium Carbonate Anhydrous.

Which of these should I use?


Thanks for your help,
Bill

[xiankai]

so 50 = 53.57 mg carbonate needed per liter

this is the carbonate ion, CO₃^2-, not sodium carbonate, Na₂CO₃.

in order to find the mass of sodium carbonate needed, u must make use of the molar ratio,

which is that Na₂CO₃ = CO₃^2-, in terms of moles.

Could you please explain the calculate to moles I don't know what that means?

1 mole of substance is roughly speaking, the relative atomic mass (A_r) of an element in grams. u can look it up in any periodic table like on this site for instance, just look for atomic weight of '...'

then there is the following formula:

n = m/M

where
n = number of moles
m = mass of substance
M = molar mass of substance (the sum of all the A_r of the elements included)

so from here, you convert the mass of carbonate needed into moles, and multiply the same amount of moles by the molar mass of sodium carbonate. this will give u the mass of sodium carbonate per liter.

I saw two different forms of sodium carbonate for sale, Sodium Carbonate Monhydrate and Sodium Carbonate Anhydrous.

the first is Na₂CO₃.H₂O, while the latter is just plain Na₂CO₃.

since the latter offers a higher concentration of sodium carbonate per gram, i would suggest it.