邊度有兩個Ca reactant
佢step 1係mix NaOH and CaCl2 to form Ca(OH)2
Ca(OH)2 slightly soluble 當佢saturated時會form Ca(OH)2(s) 即係果2.222g precipitate
filter後個solution就係saturated Ca(OH)2(aq)
再add excress K2SO4 to form CaSO4(s) 即係6.81g precipitate
所有Ca2+分別去曬Ca(OH)2(s)同CaSO4(s)度
簡單講 個實驗加NaOH其實無乜實際意義 直接加excess K2SO4都做到
不過出題計算上煩一煩你咁解