Elemental sulfur can be used to control outbreaks of powdery mildew on grapes - VCE - SSCE Chemistry - Question 10 - 2009 - Paper 1
Question 10
Elemental sulfur can be used to control outbreaks of powdery mildew on grapes. However, sulfur remaining on the grapes after harvest can be converted to a number of ... show full transcript
Worked Solution & Example Answer:Elemental sulfur can be used to control outbreaks of powdery mildew on grapes - VCE - SSCE Chemistry - Question 10 - 2009 - Paper 1
Step 1
Determine the concentration of barium ions remaining in the 10.00 mL sample solution.
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Answer
To determine the concentration of barium ions remaining in the sample solution, we first refer to the calibration curve which shows the relationship between the absorbance and concentration of barium ions in solution. From the graph, we can find that an absorbance of 0.11 corresponds to a concentration of approximately 23 mg/L of Ba<sup>2+</sup> ions. This indicates that the concentration of barium ions remaining in the 10.00 mL sample solution is:
CBa2+=23extmg/L
Step 2
Determine the mass of barium ions in the 10.00 mL sample solution.
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Answer
To find the mass of barium ions, we use the formula:
mBa2+=CBa2+imesV
where:
mBa2+ is the mass of barium in mg
CBa2+ is the concentration of barium ions in mg/L
V is the volume of the solution in L
Substituting the values: m_{Ba^{2+}} = 23 ext{ mg/L} imes rac{10.00 ext{ mL}}{1000 ext{ mL}} = 0.23 ext{ mg}
Thus, the mass of barium ions remaining in the 10.00 mL sample solution is 0.23 mg.