Question

of limestone and other soil materials was ed the limestone decomposed to give ali ned, and side and carbon dioxide. CaCO3(s) - CO(x) + CO. 1.506-sample of limestone-containing materiale 0.558 g of CO, in addition to CaO, after being heated at a high temperature. What was the mass percent of CaCO, in the original sample? 14 pel 15 An unknown compound has the formula C,H,O, You V. burn 0.0956 g of the compound and isolate 0.1356 of Co, and 0.0833 g of H.O. What is the empirical formula of the compound? If the molar mass is all 62.1 g/mol, what is the molecular formula? ( p/s) If 6.73 g of Na,CO, is dissolved in enough water to make 250 ml. of solution, what is the molar concentra tion of the sodium carbonate? What are the molar cory centrations of the Naand Co,-ions? 3 ) 1 If you dilute 25.0 mL of 1.50 M hydrochloric acid to 500 ml, what is the molar concentration of the dilute apk) acid? 18. What is the hydronium ion concentration of a 0.0013 M solution of HNO,? What is its pH? episy

Answer 1

Here is the Solution:

The balanced chemical equation for the given reaction is, CaCO3 (3) CaO (6) + CO2(g) from the balanced chemical equation , 1 mol of coz is produced from 1 mal of CaCO₃ The mass of CO₂ is given : 0.558 g The molar mass of CO2 is: 44.01 g/mol The sample of limestone contains : 1.506 g (mass) The molar mass of caloz is: 100,0869 g/mol I first calculate how many moles of coz we have. moles co₂ = mass 0.558 g = 0.01267894 mol molar mass coa 44.018/mol a mol Since, 1 mol of CO2 is produced from 1 mol of calO3, the amount of Caloz in the sample must also have 0.01267894 mol Second, calculate the mass of Ca(O3. mass CaCO3 = moles x molar mass mass Ca (Oz = 0.0 1 2 6 7 8 94 motx 100.0869 g mot mass calO₃= 1.2689 g Now, we can calculate the mass percent of caloz Mass percent = 1.2689 1.506 & Mass percent = 84.25 % / - X 100%

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