A pure gold ring with a volume of 1.57 cm cubed is initially at 11.4*C. When it is put on it warms up to 29.5*C. How much heat did the ring absorb? Density of gold is 19.3g/cm cubed. Sorry about all these chemistry questions, I really am usually good at this stuff... I've lost my mind today though. Please help! Thanks in advance... Angel
2006-09-26 08:18:22 · 4 answers · asked by Angel Eve 6 in Science & Mathematics ➔ Chemistry
O yes... Could you please explain how you solved it too... Thats where I need the help. Thanks
2006-09-26 08:19:03 · update #1
1.57 cm^3 x 19.3 g/cm^3 = 30.301 g gold
you forgot the heat capacity of gold, which is .128 J/(g K) (CHECK YOUR BOOK AND LOOK THIS UP, DIFFERENT BOOKS GIVE DIFFERENT VALUES AND YOU'LL GET IN TROUBLE IF IT'S THE WRONG ONE).
change in heat = heat capacity of gold x mass of gold x temperature change
change in heat = .128 J/(g K) x 30.301 g gold x (29.5 C - 11.4 C)
= .128 J/(g K) x 30.301 g gold x 18.1 K
= 70.2013568 J -> 70.2 J
(lowest amount of significant figures used in the problem is 3, so round up to 3 significant figures)
the temperatures are supposed to be converted into kelvins (K), but since you're just taking the difference of the two, you didn't need to add 273.15 to each of the celsius temperatures, which is how you convert from celsius to kelvin. if you wanted to, it would be 302.65 K - 284.15 K, which if you noticed, is still 18.1 K.
2006-09-26 08:40:32 · answer #1 · answered by johnny m 2 · 0⤊ 0⤋
I'm missing a bit of information here...
You know the volume v and density d of the ring. So the mass of the ring is m = d x v = 30.3 g.
Now you need the "specific heat" of gold, which I recall has the units of cal / (gram x deg. Celsuis). The change in temperature is 18.1 degrees, so multiplying 18.1 x 30.3 x Specific Heat should get you the answer you need.
2006-09-26 08:31:37 · answer #2 · answered by Polymath 5 · 0⤊ 0⤋
find the mass of the gold using density and volume, then find the change in temperature, then use the formula, H=M*S*T where, m=mass,S=specific heat,T=change in temperature...
2006-09-26 08:29:24 · answer #3 · answered by ashwin_hariharan 3 · 0⤊ 0⤋
Q = msdT
Q : Heat energy
m : mass in g
s : specific heat capacity JK-1g-1
dT : Change in temp
Q = 19.3 * 1.57 * 0.1291 * 18.1 = 70.8J
2006-09-26 08:29:36 · answer #4 · answered by vnav_in 2 · 0⤊ 0⤋