90 cm³ of 0.01M calcium hydroxide were added to a sample of water containing 0.001 moles of calcium hydrogen carbonate

90 cm³ of 0.01M calcium hydroxide were added to a sample of water containing 0.001 moles of calcium hydrogen carbonate
a) Write an equation for the reaction which took place
b) Calculate the number of moles of calcium ions in 90 cm³ of 0.01M calcium hydroxide.
c) What would be observed if soap solution was added dropwise to a sample of the water after the addition of calcium hydroxide? Give a reason.

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a) Ca(OH)₂(aq)+ Ca(HCO₃)₂(aq) $\rightarrow$ 2CaCO₃(s) + 2H₂O(l)

b) Moles = $\frac{volume\times Molarity}{1000}$, Moles of Ca²⁺ = $\frac{90 \times 0.01 }{1000}$ = 0.0009 moles

c) Water will still be hard since not all calcium ions will have been precipitated when soap is added it initial;y forms scam then later produces lather

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johnmulu answered the question on February 10, 2017 at 13:40

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