Part-I Question-1 mass of sodium bicarbonate used = 0.323g number of moles of so
ID: 700286 • Letter: P
Question
Part-I
Question-1
mass of sodium bicarbonate used = 0.323g
number of moles of sodium bicarbonate = given mass/ molar mass
= 0.323/(23+1+12+(3x16)) = 0.323 / 84 =0.0038 moles
question – 2
number of moles of sodium chloride collected = 0.229 / (23+35.5) = 0.229/58.5 =0.0039 mole
Question-3
divide both of them with the lowest number of moles to get simplest mole to mole ratio
ie, lowest values is , 0.0038
therefore divide , 0.0038/0.0038 = 1 and 0.0039/0.0038 =1.0263
Question-4
rounding the answers, then 1 and 1 or 1:1
Part-II
question-1
balanced Chemical reaction HCl(aq) + NaHCO3(s) NaCl(aq) + H2O(l) + CO2(g)
Molecular masses 36.5g 84g 58.5g 18g 44g
number of moles 1 mole 1 mole 1 mole 1 mole 1 mole
their ratios are 1:1
theoretical yield is from 84g of NaHCO3 is 58.5 g NaCl
so from 1 g of NaHCO3 , it will be 58.5/84g NaCl
here, 0.323 g of NaHCO3 used, therefore 0.323 x (58.5/84) = 0.2249 g of NaCl will get(expecting)
but here 0.229 of NaCl obtained.
Therefore yield is (0.229/0.2249)x100=101%
For sodium carbonate and HCl
Chemical reaction : 2HCl(aq) + Na2CO3(s) 2NaCl(aq) + H2O(l) + CO2(g)
Molar masses : 2x35.5=73g 106g 2x58.5=117g 18g 44g
number of moles of sodium carbonate = given mass/ molar mass
= 0.453/106 =0.0042moles
number of moles of NaCl = 0.459/58.5 =0.0078g
simplest whole number ratio is 0.0042/0.0042 = 1 and 0.0078/0.0042 =1.8571
After rounding = 1:2
expected yield = 0.453 x (117/106) =0.5g
but obtained yield is 0.459g
Therefore,Percent yield = (obtained yield/expected yield ) x 100
= (0.459/0.5) x 100 = 91.8%
Explanation / Answer
1.) Use your data to determine the experimental mole-to-mole ratio between sodium bicarbonate and sodium chloride.
a.) Convert the mass of sodium bicarbonate used to moles.
b.) Convert the mass of sodium chloride collected to moles.
c.) Divide both of your results from the preceding two steps by the lower mole value to determine the simplest mole-to-mole ratio between sodium bicarbonate and sodium chloride.
d.) simplest mole ratio before and after rounding
2) Determine your percent yield of sodium chloride in reaction
a.) Write the balanced equation for reaction A – the reaction between sodium bicarbonate and hydrochloric acid.
b.) Using mass-to-mass stoichiometry, calculate the theoretical yield of NaCl for reaction A. Use your initial mass of sodium bicarbonate reactant as a starting point, along with the relevant mole ratio from the balanced equation to perform this calculation.
c.)Calculate your percent yield of sodium chloride product.
For sodim carbonate and hydrocloric acid - 2nd set of data
1) Use your data to determine the experimental mole-to-mole ratio between sodium carbonate and sodium chloride.
a.) Convert the mass of sodium carbonate used to moles.
b.) Convert the mass of sodium chloride collected to moles.
c.)Divide both of your results from the preceding two steps by the lower mole value to determine the simplest mole-to-mole ratio between sodium carbonate and sodium chloride.
d.) simplest mole ratio before and after rounding
2) Determine your percent yield of sodium chloride in reaction B.
a.) Write the balanced equation for reaction B – the reaction between sodium carbonate and hydrochloric acid. •
b.) Using mass-to-mass stoichiometry, calculate the theoretical yield of NaCl for reaction B. Use your initial mass of sodium carbonate reactant as a starting point, along with the relevant mole ratio from the balanced equation to perform this calculation.
c.) Calculate your percent yield of sodium chloride product.
3) Is your percent yield here for reaction B greater than or less than 100%? Give one possible source of error that could explain the percent yield you obtained.
Mole Ratios and Reaction Stoichiometry Reaction A: Sodium Bicarbonate and Hydrochloric Acid Experimental Data (a) Mass of evaporating dish+ watch glass (b) Mass of evaporating dish + watch glass +sodium bicarbonate (c) Mass of sodium bicarbonate used (d) Mass of evaporating dish + watch glass + sodium chloride (e) Mass of sodium chloride collected (experimental yield) O 3239 Reaction B: Sodium Carbonate and Hydrochloric Acid Experimental Data (a) Mass of evaporating dish + watch glass (b) Mass of evaporating dish+ watch glass + sodium carbonate 47.393 (c) Mass of sodium carbonate used (d) Mass of evaporating dish + watch glass + sodium chloride 7.399 (e) Mass of sodium chloride collected (experimental yield) 4539 0459