# Chemistry

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Performing the same experiment described on your lab manual, a student used a 0.358 g sample of Alka-Seltzer and the mass of CO2 was found to be 0.102 g. Based on this result, answer the following questions:

Determine the mass of NaHCO3 that produced the CO2 in the experiment.
0.195

Determine the % mass of NaHCO3 in the sample.

Determine the mass of NaHCO3 in the tablet assuming the mass of the tablet is 3.50 g.
How do i do the second and third questions?

• Chemistry - ,

I answered this same question for someone earlier but I can't find it. I think I erred in that post because I don't know the reaction. What are the conditions under which the loss of CO2 occurred?
Is that a titration experiment or was the tablet heated? If heated, at what T?

• Chemistry - ,

OK. I found the other post and you're the one who posted it. Therefore, disregard that post until you answer the questions about how the tablet was treated.

• Chemistry - ,

reaction between NaHCO3 and HCl

• Chemistry - ,

I did the equation of the % mass but its wrong

• Chemistry - ,

I want to know how the tablet was treated. You make reference in the problem to "Performing the same experiment described on your lab manual, a student used a 0.358 g sample of Alka-Seltzer ......." So you know how the sample was treated but I don't. Was it titrated with something such as HCl? heat to drive off CO2. If so what temperature was used.

• Chemistry - ,

HCl is added to NaHC03 .

• Chemistry - ,

HCl + NaHCO3 => H2O + CO2 + NaCl

Convert the 0.102 g CO2 to g NaHCO3.
0.102g CO2 x (molar mass NaHCO3/molar mass CO2) = 0.102 x 84/44 = 0.195.
Is that 0.195 you posted what you obtained.
Then %NaHCO3 = (0.195/0.358)*100 = about 54.4%. Check that.
If your earlier reply meant you tried these numbers and the data base said it was wrong then I need the procedure written out for me. This answer is right for what you've posted.

• Chemistry - ,

Yes its correct, but how about he mass of NaHCO3 in the tablet assuming the mass of the tablet is 3.50 g

• Chemistry - ,

That must be for a part of the problem you didn't post.

If the tablet is 54.4% NaHCO3 and the tablet has a mass of 3.50 g, then plug these numbers into the % formula and calculate mass NaHCO3.
(mass NaHCO3/mass tab)*100 = %
(x/3.50)*100 = 54.4
Solve for x = mass NaHCO3.