AP Chem

A sample of solid KCl (potassium chloride) weighing 0.500 g is mixed with an unweighed sample of solid MgCl2 (magnesium chloride) and the mixture is then completely dissolved in water to form a clear solution. An aqueous solution of AgNO3 (silver nitrate) is then added to this mixture. A reaction occurs and insoluble solid AgCl (silver chloride) is precipitated. The equation for the reaction is as follows:

KCl(aq) + MgCl2(aq)+ 3AgNO3(aq) KNO3(aq)+ Mg(NO3)2(aq)+ 3AgCl(s)

When the reaction is over, both of the original chlorides, KCl and MgCl2, are completely used up. Analysis shows that 8.486 g of AgCl has been produced. Find the mass of the MgCl2 sample used to make the solid mixture.

Use the following atomic masses: Ag = 107.87, Cl = 35.45, K = 39.10, Mg = 24.31, N = 14.01

asked by benji
  1. Wouldn't this work. Check my thinking.
    Calculate how much AgCl can be pptd from 0.500 g KCl. That will be
    0.500 g KCl x (molar mass AgCl/molar mass KCl) = ?? g AgCl.
    Subtract 8.486 - ??g AgCl from the above calcn to arrive at the amount AgCl that must be due to MgCl2 alone.
    Then convert g AgCl that must be due to MgCl2 to g MgCl2 and you have it solved. I did a very quick quickie on the numbers and came up with approximately 2.7 grams MgCl2 but you need to check that carefully.

    posted by DrBob222
  2. I ended up getting 1.24 g?

    posted by benji
  3. My answer, after reviewing it, is 2.499 grams MgCl2.
    I used 95.21 for molar mass MgCl2.
    143.32 for molar mass AgCl
    74.55 for molar mass KCl.

    posted by DrBob222
  4. i keep getting 1.24 g i first coverted 0.500g KCl to g of AgCl g and i got 2.88 g. then i subtracted that from 8.486 and i got 5.602 AgCl. then i converted 5.602 g of AgCl to g of MgCl2 and i got 1.24 g.
    are your numbers similar to that?

    posted by benji

Respond to this Question

First Name

Your Response

Similar Questions

  1. chemistry

    A sample of solid KCl (potassium chloride) weighing 0.500 g is mixed with an unweighed sample of solid MgCl2 (magnesium chloride) and the mixture is then completely dissolved in water to form a clear solution. An aqueous solution
  2. Chemistry

    A 10.00 gram solid sample consisting of a mixture of sodium chloride and potassium sulfate is dissolved in 100.0 mL of water is combined with another 200.0 mL solution that contains excess aqueous lead(II) nitrate. Upon mixing the
  3. chemistry

    thanks for any help with these translations into scientific notation: 1. magnesium ribbion is dropped into an aqueous solution of hydrochloric acid 2. a solid peice of copper is burned in pure oxygen 3. zinc carbonate is strongly
  4. chemistry

    write a balanced chemical reaction for the reaction of aqueous magnesium chloride with aqueous potassium phosphate to form solid magnesium phosphate (Mg3(PO4)2) and aqueous potassium chloride (KCl). Indicate the physical states of
  5. Chemistry

    You are going to be provided with 1 0.50 g sample of magnesium oxide. Treatment of this sample with hydrochloric acid (HCl) will take all of the MAGNESIUM in the oxide and change it into magnesium chloride, MgCl2 You will add 100
  6. chemistry

    a mixture containing only sodium chloride and potassium chloride has a mass of 4 g. when this sample is dissolved in water and excess silver nitrate is added a white solid forms. after filreation and drying the solid silver
  7. chemistry

    Solid magnesium metal reacts with chlorine gas according to the following equation: Mg + Cl2 --> MgCl2 What mass of magnesium chloride is formed in the reaction between 7 g of Mg and 13.2 g of Cl2
  8. chemistry

    Solid magnesium metal reacts with chlorine gas according to the following equation: Mg + Cl2 --> MgCl2 What mass of magnesium chloride is formed in the reaction between 7 g of Mg and 13.2 g of Cl2
  9. chemistry

    Solid magnesium metal reacts with chlorine gas according to the following equation: Mg + Cl2 --> MgCl2 What mass of magnesium chloride is formed in the reaction between 7 g of Mg and 13.2 g of Cl2 is this correct 7 g+13.2 g =
  10. chemistry

    Solid magnesium metal reacts with chlorine gas according to the following equation: Mg + Cl2 --> MgCl2 What mass of magnesium chloride is formed in the reaction between 7 g of Mg and 13.2 g of Cl2 I got 7/24.3= .288 13.2/70.90=

More Similar Questions