[Chem] Determining Masses from Concentration

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SUMMARY

This discussion focuses on calculating the masses of magnesium chloride (MgCl2) and sodium chloride (NaCl) from a 0.6118 g sample after a reaction with 145 mL of 0.1006 M silver nitrate (AgNO3). The formation of 1.7272 g of silver chloride (AgCl) precipitate is central to the calculations. Participants emphasize the importance of writing the precipitation reaction to establish the mole ratio and suggest that the number of moles of AgCl can be derived from its mass, which is essential for determining the masses of the original components.

PREREQUISITES
  • Understanding of molarity and the equation M = mol / L
  • Knowledge of precipitation reactions and stoichiometry
  • Familiarity with calculating moles from mass
  • Basic skills in chemical equations involving silver nitrate and its precipitates
NEXT STEPS
  • Learn how to balance precipitation reactions involving silver nitrate and its products
  • Study the calculation of moles from mass using molar mass
  • Explore stoichiometric relationships in chemical reactions
  • Investigate the concept of limiting reagents in chemical reactions
USEFUL FOR

Chemistry students, laboratory technicians, and educators looking to deepen their understanding of stoichiometry and precipitation reactions in analytical chemistry.

dt_
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Homework Statement


In lab, a student decides to analyze a 0.6118 g sample containing only magnesium chloride and sodium chloride. He does this by adding 145 milliliters of 0.1006 M silver nitrate. A precipitate, silver chloride, is formed, which has a mass of 1.7272 grams. Using this data, calculate the mass of each of the original sample's components.

Homework Equations



M = mol / L

MgCl_{2} + NaCl + AgNO_{3} ...?

The Attempt at a Solution



I'm not really sure where to start here; my instinct is to multiply the volume of the silver nitrate by its molarity to get the number of moles. But I'm not sure what to do next, and I don't know what the products of the reaction are, other than the silver chloride precipitate. And besides, how would I able to find out how much mass there is of the individual components in the original sample if the problem only gives the total mass of these two components? Can anyone help me out? (Thanks in advance! :))
 
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dt_ said:

Homework Statement


In lab, a student decides to analyze a 0.6118 g sample containing only magnesium chloride and sodium chloride. He does this by adding 145 milliliters of 0.1006 M silver nitrate. A precipitate, silver chloride, is formed, which has a mass of 1.7272 grams. Using this data, calculate the mass of each of the original sample's components.


Homework Equations



M = mol / L

MgCl_{2} + NaCl + AgNO_{3} ...?

The Attempt at a Solution



I'm not really sure where to start here; my instinct is to multiply the volume of the silver nitrate by its molarity to get the number of moles. But I'm not sure what to do next, and I don't know what the products of the reaction are, other than the silver chloride precipitate. And besides, how would I able to find out how much mass there is of the individual components in the original sample if the problem only gives the total mass of these two components? Can anyone help me out? (Thanks in advance! :))


Start by writing out the precipitation reaction. This will give you the ratio of moles of silver chloride to moles of magnesium chloride plus sodium chloride.
Do you know how to determine the number of moles of silver chloride produced with the given data?
Hint: more data is given to you than you need to answer this question. Which data is unnecessary?
 
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