Answer:
Explanation:
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In this case, since the decomposition of sodium hydrogen carbonate is:
Thus, since there is a 2:1 mole ratio between the sodium hydrogen carbonate and sodium carbonate, and the molar masses are 84.01 and 105.99 g/mol respectively, we obtain the following theoretical yield:
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Answer:
A. 266g/mol
Explanation:
A colligative property of matter is freezing point depression. The formula is:
ΔT = i×Kf×m <em>(1)</em>
Where:
ΔT is change in temperature (0°C - -0,14°C = 0,14°C)i is Van't Hoff factor (1 for a nonelectrolyte dissolved in water), kf is freezing point molar constant of solvent (1,86°Cm⁻¹) and m is molality of the solution (moles of solute per kg of solution). The mass of the solution is 816,0g
Replacing in (1):
0,14°C = 1×1,86°Cm⁻¹× mol Solute / 0,816kg
<em>0,0614 = mol of solute</em>.
As molar mass is defined as grams per mole of substance and the compound weights 16,0g:
16,0g / 0,0614 mol = 261 g/mol ≈ <em>A. 266g/mol</em>
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The paper is not clear so please ask your problem again with more clear print
PH of acidic buffer = pKa + log [CH₃COONa - HCl] / [CH₃COOH + HCl]
pKa of CH₃COOH = 4.74
Concentration of acetic acid in buffer = 2.0 M
Concentration of sodium acetate = 1.0 M
Concentration of HCl must add = x
pH = 4.74 + log (1-x) / (2+x) = 4.11
x = concentration of HCl must be added = 0.43 M
number of moles of HCl = M * V = 0.43 * 1 = 0.43 mol
mass of HCl must be added = 0.43 * 36.5 = 15.7 g
The answer is 0.0035
In order to figure out kg, you have to know that 1 milligram is equal to 1/100000 kilograms. You take the amount of mg's that you have, which is 3500, and divide it by 1000000 which will give you your answer.
3500/1000000= 0.0035 kg
