We had an experiment in my chem lab. We used NaCO3(s), HCl (aq) and color indica

Question

We had an experiment in my chem lab. We used NaCO3(s), HCl (aq) and color indicator to see how much NaCO3(s) do we need to add for all the CO2 to leave the solution and the solution to change color. The fist table shoes how much NaCO3(s) was used for the desired reaction. My question is in regards to the second table. How do we solve for the moles of HCl used and what are they. Please be mindful of the units.

NaCOs Used 0.50M 0.303 0.434 0.635 0.972 0.25M HCI 10 mL 15 mL 0.447 20 mL 30 mL 30M 0.272 0.39 0.485 0.631 L 0.26 10.426 10.595 Moles of HCI Used 0.25M 30M 0.50M 0.01 L 0.015 L 0.02 L 0.03 L

Explanation / Answer

number of moles = molarity * volume
For 0.01 L:
If 0.25 M is used,number of moles = M*V = 0.25*0.01 = 0.0025 mol
If 0.3 M is used,number of moles = M*V = 0.3*0.01 = 0.003 mol
If 0.5 M is used,number of moles = M*V = 0.5*0.01 = 0.005 mol

for 0.015 L,
If 0.25 M is used,number of moles = M*V = 0.25*0.01 5= 0.00375 mol
If 0.3 M is used,number of moles = M*V = 0.3*0.015 = 0.0045 mol
If 0.5 M is used,number of moles = M*V = 0.5*0.015 = 0.0075 mol
40 % has decomposed. so remaining = 60 % of original

Similarly you can find number of moles for 0.02 L and 0.03 L

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