# Stoicheometry Vlab

## Stoicheometry Vlab

• Date Submitted: 03/09/2009 3:58 AM
• Category: Science
• Words: 332
• Page: 2
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I. Purpose: The purpose of this lab is to react NaHCO3 with excess HCl, calculate its mole ratio between both the NaHCO3 and NaCl, then balance out the equation for this reaction, and determine whether or not it supports the law of conservation of mass.
II. Data and Observations:
a. Mass of empty evaporating dish 42.33 g
b. Mass of evaporating dish + NaHCO3 45.48 g
c. Mass of evaporating dish + NaCl 44.51 g

III. Calculations:
1. Mass of NaHCO3_: (Mass of evaporating dish + NaHCO3 ' Mass of empty evaporating dish = Mass of NaHCO3) '' (45.48 g ' 42.33 g) = 3.15 g NaHCO3
2. Mass of NaCl: (Mass of evaporating dish + NaCl ' Mass of empty evaporating dish = Mass of NaCl) '' (44.51 ' 42.33) = 2.18 g NaCl
3. Moles of NaHCO3: 3.15 g NaHCO3 x (1 mole NaHCO3/84.0 g NaHCO3) = .0375 mole NaHCO3
4. Moles of NaCl: 2.18 g x (1 mole NaCl/58.5 g NaCl) = .0373 mole NaCl
5. For this reaction NaHCO3 + HCl '' NaCl + CO2 + H2O there are no coefficients everything is balanced, the ratio has to be 1:1/
IV. Questions:
1. 2NaHCO2 + Cl2 '' 2NaCl + 2CO3 + H2O
2. 2:2 which can further be reduced to 1:1. This answer compares with mole ratio #5 because its simply 1:1 rather than 2:2 in an equation
V. Conclusion:
The Law of Conservation of Mass states that no matter is lost in a reaction. If one has all but one mass value it would follow that one has all the masses of either the reacts or the products. All one must do is add all of the masses the products or reactants together then subtract the masses of the known reactants or products. The resulting answer will successfully be the unknown mass.In a balanced chemical equation, all reactants and products must be represented
by symbols or formulas. The total number of atoms of each element must be the
same on each side of the equation to satisfy the Law of Conservation of Mass. A
Calculation of the formula mass of a reactant or product enables us to convert
from mole relationship given by the coefficients of the balanced