How much heat (kJ) is required to completely melt 30.5 grams of ice at 0 oC ?
anddddd
Which of the following are true statements ?
a) The triple point of H2O is -4oC and 4.58 atm
b) At 5 atm and −78oC solid CO2 will not sublime
c) The freezing temperature of a substance is less dependent on pressure than is its boiling boint
d) At 20 atm and −78oC CO2 is in the liquid phase
2007-11-08 15:29:05 · 4 answers · asked by matt b 1 in Science & Mathematics ➔ Chemistry
First question is about specific heat. If memory serves, ice has a specific heat of 2090 J / ( kg x *C ), the heat of fusion ( melting ) is 3.34e5 J / kg. So, it will take 63.745 J for every degree this mass of ice is warmed ( whatever the starting temperature is. ) After that it will take 10187 J to melt this mass of ice.
As for the other question, you'll need to consult the phase diagrams for water and carbon dioxide in your chem book to check them out. I can't find any reliable ones right now.
2007-11-08 15:41:16 · answer #1 · answered by lancingdragon 2 · 0⤊ 0⤋
Multiple choice = c.
Somewhere you have a latent heat of fusion for water in kJ/gram. Just multiply that value by 30.5 g
2007-11-08 15:43:42 · answer #2 · answered by cattbarf 7 · 0⤊ 0⤋
attempt this--each and each question is a convert ## to &&. think of of it as a fraction of powers of 10. working example, 17.2 s to ms is 17.2 x 10^0/10^–3 = 17.2 x 10^3. 2.fifty six mm to km could be 2.fifty six x 10^–3/10^3 = 2.fifty six x 10^–6. this methodology continuously works for metric form conversions. that's no longer a dimensional prognosis attitude although. The final one is rather convert 17.3 mL to L, by using fact one million cm3 = one million mL so the undertaking is 17.3 mL to L! wish this helps!
2016-10-15 13:33:29 · answer #3 · answered by goldthorpe 4 · 0⤊ 0⤋
i have no idea. im really sorry. chemistry is so hard, im in it now & wow. i know how you feel :[ good luck!
2007-11-08 15:39:28 · answer #4 · answered by Anonymous · 0⤊ 0⤋