Question

Help please.
Limestone is impure CaCO3. Excess HCl was added to 1.50g of crushed limestone and the carbon dioxide evolved was collected. 330cm^3 of carbon dioxide was collected at a temperature of 295K and a pressure of 1.01x10^5 Pa. Assume that no carbon dioxide was lost by solution by HCl. Calculate: 1) the number of moles of carbon dioxide formed. 2) the mass of the CaCO3 in the limestone and 3) The % of CaCO3 in the limestone.

Answer 1

@Nnesha @abb0t please help me? I just need some guidance.

Answer 2

You actually don't need to know the reaction at all to answer this question, just use the information already provided. The order in which you are asked questions also gives you hints about the process you'll want to follow.

For the first part, use PV=nRT and solve for n to determine the moles of CO2 formed. Be sure you're working in appropriate units!

For the second part, the only place that the carbon atoms in CO2 can come from is from the CaCO3 that reacts. Since there's 1 carbon atom per CO2, and 1 carbon atom per CaCO3, for however many moles of CO2 that were produced, the same number of moles of CaCO3 reacted! Therefore, just multiply the moles you've just found by the molar mass of CaCO3!

For the third part, divide the mass you've just found by the total mass of the sample and multiply by 100 - this is the % purity.

Answer 3

Got it! Thank you sooooo much! :))