Q1. A 0.5 g mixture of Cu2O and CuO contain 0.425 g Cu. What is the mass of CuO in the mixture?

Q2. A chemist wants to prepare 0.5 M HCl. The label of a commercial hydrochloric acid shows that S.G. =1.18 and concentration of HCl was 37%. Calculate the volume of commercial hydrochloric acid dose the chemist requires to make up 1.5 L of the dilute acid.

Q3. Relate the rate of decomposition of NO2 to the rate of formation of O2 for the following reaction.


  1. 👍 0
  2. 👎 0
  3. 👁 1,863
  1. #2. Determine the molarity (M) of the concentrated acid.
    1000 mL x 1.18 g/mL x 0.3 x (1/36.5) = ?M My estimated value for this is 12M but you need to refine the answer.
    Then use the dilution formula of
    mL1 x M1 = mL2 x M2
    mL1 x 12 = 1,500 x 0.5
    Solve for mL of the 12 M HCl to use.
    To prepare you drop ? of the conc HCl into a 1.5 volumetric flask and make to the mark with distilled water. Mix thoroughly and stopper.

    1. 👍 1
    2. 👎 0
  2. #1. I work these as two equations and solve them simultaneously.
    Let X = mass CuO
    and Y = mass Cu2O
    equation 1 is X + Y = 0.5

    Equation 2 comes from this. The grams copper from CuO + copper from Cu2O = 0.425g. With MM standing for molar mass and AM for atomic mass:
    Grams Cu from CuO is (AM Cu*X/MM CuO)

    Grams Cu from Cu2O is (2*AM Cu*Y/MM Cu2O)

    Put that together for equation 2 as follows:
    (AM Cu*X/MM CuO) + (2*AM Cu*Y/MM Cu2O) = 0.425

    Solve equation 1 and equation 2 for X = grams CuO
    Post your work if you get stuck.

    1. 👍 2
    2. 👎 0
  3. Thank you very much!

    1. 👍 0
    2. 👎 0
  4. for #2
    Why the equation need to x 1000 ?

    1. 👍 0
    2. 👎 0
  5. 0.212 g CuO

    1. 👍 2
    2. 👎 0
  6. #1=0.216GRAMS

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Chemistry

    A dry mixture of kno3 and sand could be separated by 1. adding water to the mixture and filtering 2. adding water to the mixture and evaporating 3. heating the mixture to a high temperature 4. cooling the mixture to a low

  2. Science

    A small bowl contains a mixture of toothpicks and glass marbles.The easiest way to separate the mixture without touching it would be to A.add glue to the mixture a magnet in the bowl C.pour the mixture into a paper cone

  3. Chemistry

    A mixture contains 0.250 mol of Mn2O3 and 20.0 g of MnO2. 1.How many atoms of oxygen are present in the mixture? 2.How many grams of manganese are in the mixture?

  4. Chemistry

    help - confusion :( The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process, 2 Cu2O + O2 --> 4CuO The change in enthalpy upon reaction of 75.30 g of Cu2O(s) is -76.83 kJ. Calculate the

  1. Chemistry

    Given: Cu2O(s) + 1/2 O2(g) → 2CuO(s) deltaH°= -144 kJ 2Cu2O(s) → 2Cu(s) + 2CuO(s) deltaH°= 22 kJ Calculate the standard enthalpy of formation of CuO(s).

  2. Chem-organic, bio, intro

    A gas mixture contains oxygen and argon at partial pressures of 0.60 atm and 425 mmhg. If nitrogen gas added to the sample increases the total pressure to 1250 torr, what is the partial pressure in Torr of the Nitrogen added?

  3. Another Physics

    At some point in the combustion cycle of an engine, the temperature of a combusted air-fuel mixture is 582 degrees Celsius. Given that the pressure in the mixture is 6.2 bar, determine the density of the mixture (in kilogram per

  4. mole fraction

    A solution contains a mixture of pentane and hexane at room temperature. The solution has a vapor pressure of 241 torr. Pure pentane and hexane have vapor pressures of 425 torr and 151 torr, respectively, at room temperature. What

  1. chemistry

    3. Use the mole ratio of CuO produced per mole of malachite to write a balanced equation for the malachite decomposition reaction. Assume that CO₂ is also a product of the decomposition. CuCo3*Cu9OH)2 -----> 2Cuo+Co2+H2O

  2. Chemistry

    I am trying to answer my questions for thermal decomposition of malachite lab. I have moles of malachite in 1g= 0.0045 moles of Cuo produced= 0.0009 ratio of moles of Cuo produced per moles of malachite

  3. chemistry

    A 1.500-g sample of a mixture containing only Cu2O and CuO was treated with hydrogen to prduce 1.252 g pure copper metal. Calculate the percentage composition (by mass) of the mixture.

  4. chemistry

    An unknown mixture containing KClO3 was added to an ignition tube weighting 41.960g, The tube and mixture was then found to weight 43.772g. After the first heating, the tube and its contents weighed 43.621g. After the second and

You can view more similar questions or ask a new question.