Chemistry

posted by .

How many joules are needed to heat 8.50 grams of ice from -10.0 degrees to 25.0 degrees

I came up with 2124 joules

  • Chemistry -

    I believe I worked that problem yesterday. Perhaps not for you.
    heat needed to move T of ice from -10 to 0
    q1 = mass x specific heat ice x delta T

    heat needed to melt the ice.
    q2 = mass x heat of fusion.

    heat needed to move T from 0 to 25.
    q3 = mass x specific heat water x delta T.

    Total heat required is q1+q2+q3.
    Post your work if you get stuck.

  • Chemistry -

    For the specific heat of ice I looked it up and found it to be 2.05 and the heat fusion to be 334

    q1 = 8.5 x 2.05 x 10 = 174.25

    q2 = 8.5 x 334 = 2839

    q2 = 8.5 x 4.184 x -25

    and that gave me a total of 2124 joules...also for my 2nd question from yesterday...

    Caculate the hydronium ion concentration and the hydroxide ion concentration in blood, the pH of which is 7.3 (slightly alkaline)

    answers:
    [hydronium ion]= 5.0 x 10^-8
    [hydroxide ion]= 2 x 10^-7

  • Chemistry -

    q1 is ok.
    q2 is ok.
    q3 (which you typed in as a second q2) is not correct because you made it a negative number. Since heat is being added it must be a positive number. You should have +889.1 J and the total should have been 3902 J but check my arithmetic.
    If you don't remember to make the sign + or - depending upon heat being added or withdrawn, you may want to write the formulas as
    mass x specific heat x (Tf-Ti) where Tf is final T and Ti is initial T.
    For 0 to 25 that will be
    8.5 x 4.184 x (25-0) = a + number
    It works for the -10 to 0 also.
    8.5 x 2.05 x [0-(-10)] = 8.5 x 2.05 x 10 = a + number.
    I don't remember seeing the blood problem.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. chemistry

    Can somebody please help me with this question?
  2. Chemistry

    How many joules are needed to heat 8.50 grams of ice from -10.0 degrees C to 25.0 degrees C?
  3. Chemistry

    1)How many joules are needed to heat 8.50 grams of ice from -10.0 degrees to 25.0 degrees?
  4. chemistry

    3.) A 5.00 x 10^2 g block of metal absorbs 5016 joules of heat when its temperature changed from 20 degrees C to 30 degrees C. Calculate the specific heat of the metal. I used the formula and came with two answers 100.32 joules and …
  5. Chemistry

    How many joules of heat are needed to heat 25.0 g of ice at -5.0 degrees celcius to a final temperature of 40.0 degrees celcius?
  6. chemistry

    a 100 mL {100 grams} of water at 4.0 degrees celsius is heated until its tempurture is 37 degrees celcus. if the specific heat of water is 4.18 joules/grams degrees celcus calculate the amount of heat energy needed to cause this rise …
  7. Melting Ice Chemistry

    You have an ice cube (H2O) that weighs 5 grams and is at a temperature of -10 degrees Celsius. How much heat energy(in joules) is required to melt the ice cube and raise the temperature of the resulting liquid water to 15 degrees Celsius?
  8. 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 degrees …
  9. Chemistry

    You have 23.0g of water initially at -46°C. How much energy in joules is required to heat the ice to 0°C?
  10. Chemistry

    When 22.3 mL of 1.00 M AgNO3 is mixed with 21.7 mL of 1.50 M NaCl, the temperature of the mixture rises for 21.6 degrees C to 29.7 degrees C. The mass of the aqueous mixture is 45.9 grams and its specific heat capacity is 3.94 J/grams …

More Similar Questions