Chemistry I

An unknown volume of water at 18.2 degrees celsius is added to 24.4 mL of water at 35.0 degrees celsius. If the final temperature is 23.5 degrees celsius what was the unknown volume? (assume no heat is lost to surroundings and D of water is 1.00g/mL)

  1. 👍 0
  2. 👎 0
  3. 👁 291
asked by Kelsie
  1. Heat gained by water + heat lost by water = 0.
    unknown mass H2O x specific heat x (Tf-Ti) + known mass water x specific heat x (Tf-Ti) = 0
    Tf = final T
    Ti = initial T.
    You have only one unknown; i.e., unknown mass H2O. Post your work if you get stuck.

    1. 👍 0
    2. 👎 0
  2. x= unknown mass of H2O

    x(4.184)(23.5-35) + 17.008(4.184)(23.5-18.2)=0

    -48.116x + 377.156= 0
    x = 7.84g

    d=1.00g/mL x=unknown volume
    1.00= 7.84/x
    x=7.84mL

    1. 👍 0
    2. 👎 0
    posted by Kelsie
  3. x= unknown mass of H2O

    x(4.184)(23.5-35) + 17.008(4.184)(23.5-18.2)=0
    I don't think so. Tf = final T; Ti = initial T.
    a. Isn't the initial T 18.2 and not 35 for the unknown amount of water?
    b. Where did the 17.008 come from? That must be the mass of water but that was 24.4 mL so it has a mass of 24.4 mL x 1.00 g/mL = 24.4 grams.
    c. And delta T for the known amount of water is 23.5 - 35.0 isn't it?


    -48.116x + 377.156= 0
    x = 7.84g

    d=1.00g/mL x=unknown volume
    1.00= 7.84/x
    x=7.84mL

    1. 👍 0
    2. 👎 0
  4. V = unknown volume of H2O, which equals the mass because the density is 1.00

    V(4.184)(23.5-18.2) + 24.4(4.184)(23.5-35) = 0

    22.1752V = 1174.0304

    V = 52.94mL

    1. 👍 0
    2. 👎 0
    posted by Bobby

Respond to this Question

First Name

Your Response

Similar Questions

  1. Physics 20

    1. How much heat energy is required to change 500 grams of water at 100 degrees Celsius to steam at 100 degrees Celsius? 2. How much energy is lost if 7kg of water is cooled from 46 degrees Celsius to 2 degrees Celsius? 3. How

    asked by Tamai on June 8, 2014
  2. Physics

    Please Help! I am having difficulties grasping these concepts. Explain please! 1. How much heat energy is required to change 500 grams of water at 100 degrees Celsius to steam at 100 degrees Celsius? 2. How much energy is lost if

    asked by Tamai on June 8, 2014
  3. Physics

    3/2/2016 An unknown substance at a temperature of 20 degrees Celsius is warmed up to 50 degrees when water at 80 degrees is added to it. The sum of the masses of the unknown substance and water is equal to 1000grams. In another

    asked by Marilynn on behalf of Victor Hopman on March 2, 2016
  4. Chemistry

    When 22.7mL of o.500 M H2SO4 is added to 22.7mL of 1.00 M KOH in a coffee-cup calorimeter at 23.50 degrees Celsius, the temperature rises to 30.17 degrees Celsius. Calculate the delta h of this reaction. (Assume that the total

    asked by Sean on October 19, 2012
  5. Physics

    How much heat must be added to 1-kg of 0 degrees Celsius water to turn it into water at 50 degrees Celsius? If the water had been ice at 0 degrees Celsius, would that increase, decrease, or not change the amount of energy

    asked by Teresa on October 24, 2016
  6. Physics

    The water from two buckets is mixed together. One bucket contains 5kg of water at 20 degrees Celsius and the other contains 1kg of water at 80 degrees Celsius. What is the final temperature of the mixture, assuming no heat is lost

    asked by Vincent on November 5, 2015
  7. Chemistry

    A 100g sample of water at 90 degrees celsius is added to a 100g sample of water at 10 degrees celsius. The final temperature of the water is which of the following: a) between 50 degrees celsius and 90 degrees celsius b) 50

    asked by Shellby on November 13, 2011
  8. Physics

    An unknown substance at a temperature of 20 degrees Celsius is warmed up to 50 degrees when water at 80 degrees is added to it. Can I post this question. There is more information I have and the point is to find the specific heat

    asked by Victor on October 11, 2016
  9. Chemistry

    A 11.6 g sample of an unknown metal was heated to 100.0 oC and then added to 25.0 g of water at 23.0 degrees Celsius in an insulated calorimeter. At thermal equilibrium, the temperature of the water in the calorimeter was 24.8

    asked by Abby on February 19, 2015
  10. thermochem

    An unknown volume of water at 18.2°C is added to 27.0 mL of water at 36.7°C. If the final temperature is 23.5°C, what was the unknown volume? (Assume that no heat is lost to the surroundings; d of water is 1.00 g/mL.)

    asked by james on October 5, 2008

More Similar Questions