If an Alka-Seltzer tablet has a mass of 4.953 g, and an Erlenmeyer flask containing an HCl and water solution weighs 160.351 g, what is the percent by mass of NaHCO3,in the tablet if the Erlenmeyer flask and its contents weigh 164.027 g after reaction?
Please include the rationale in providing the answer so I can learn from this :)
160.351 = mass flask and acid
+4.953 = mass tablet
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165.304 = mass flask, acid, & tablet before rxn.
-164.027 = mass flask, acid, tab after rxn
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loss in mass = 1.277 g = mass CO2 lost.
NaHCO3 + HCl ==> NaCl + H2O + CO2
Convert mass CO2 to mass NaHCO3 using the coefficients in the balanced equation, then percent NaHCO3 = (mass NaHCO3/mass tablet)*100 = ??
Check my work, especially for typos and the arithmetic. I sometimes punch the calculator incorrectly.
To find the percent by mass of NaHCO3 in the tablet, we need to determine the mass of NaHCO3 and then calculate the percentage based on the total mass of the tablet.
1. Start by finding the mass of NaHCO3 by subtracting the final mass of the Erlenmeyer flask and its contents from the initial mass of the flask and its contents after the tablet is added:
Mass of NaHCO3 = Final mass - Initial mass
Mass of NaHCO3 = 164.027 g - 160.351 g
Mass of NaHCO3 = 3.676 g
2. Now, we can calculate the percent by mass of NaHCO3 in the tablet using the following formula:
Percent by Mass of NaHCO3 = (Mass of NaHCO3 / Mass of the Tablet) x 100
Mass of the Tablet = Mass of the Alka-Seltzer tablet = 4.953 g
Percent by Mass of NaHCO3 = (3.676 g / 4.953 g) x 100
Percent by Mass of NaHCO3 ≈ 74.05%
Thus, the percent by mass of NaHCO3 in the tablet is approximately 74.05%.
Rationale:
To solve this problem, we need to understand the concept of mass percent. Mass percent represents the proportion of a particular component in a substance with respect to the total mass. In this case, we are calculating the mass percent of NaHCO3 in the Alka-Seltzer tablet.
To find the mass of NaHCO3, we subtract the initial mass of the Erlenmeyer flask and its contents (before the reaction) from the final mass of the flask and its contents (after the reaction). This gives us the mass of NaHCO3 that reacted with HCl in the flask.
Finally, we use the formula to determine the percent by mass by dividing the mass of NaHCO3 by the mass of the tablet and multiplying it by 100.