# Multiple choice help (1 Viewer)

#### horndog huang 2

##### Member Can someone help me with this q im not sure about it.. thanks !

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#### jazz519

##### Moderator
Moderator
Hey So if the caco3 is 87.4% of the limestone then the mass of the caco3 present is 87.4/100 X mass of limestone = 87.4/100 X 3.57 = 3.12018 grams convert this to moles so n(caco3)=m/mm = 3.12018/100.09 = 0.03117374363 moles. Then u write a chem equation and balance it for the reaction and remember it's an acid and carbonate reaction so u get a salt,water and carbon dioxide.
2hcl + caco3 ---> cacl2 + h20 + co2

So using mole ratios that means the amount of Hcl in moles u need is 2 times that of the caco3 so n(hcl) = 0.06234748726 moles And then u need to put this into concentration so c(Hcl) = n/v = 0.06234.../0.31 = 0.2011209266 M

Last edited:

#### horndog huang 2

##### Member
Hey heiu lol. So if the caco3 is 87.4% of the limestone then the mass of the caco3 present is 87.4/100 X mass of limestone = 87.4/100 X 3.57 = 3.12018 grams convert this to moles so n(caco3)=m/mm = 3.12018/100.09 = 0.03117374363 moles. Then u write a chem equation and balance it for the reaction and remember it's an acid and carbonate reaction so u get a salt,water and carbon dioxide.
2hcl + caco3 ---> cacl2 + h20 + co2

So using mole ratios that means the amount of Hcl in moles u need is 2 times that of the caco3 so n(hcl) = 0.06234748726 moles And then u need to put this into concentration so c(Hcl) = n/v = 0.06234.../0.31 = 0.2011209266 M
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