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1 Calculate the lculate the amount of heat released when a 225 g sample of gold

ID: 508961 • Letter: 1

Question

1 Calculate the lculate the amount of heat released when a 225 g sample of gold cools from 860 C to32.5 C. The specific he of gold is 0.129J/g C. 2 Calculate the specific heat of an unknown metal fa 32.5 g sample loses 328Jof heat when it cools from 64.0 C to 16.0°C. 3 A 1.00 kg piece Cisplaced into 100.gof water at 10.0 C. The final temperature of metal at 52.0 capacity of 42.0 J/C, calculate the of the water is 31.4 C. Assuming a coffee cup calorimeter heat specific heat of the metal. The specific heat of water is 4.18 J/g"C.

Explanation / Answer

1. given specific heat of gold = 0.129 J/g0C,

Mass of gold =225 g,

initial temperature 86 0C ,

Final emperature =32.5 0C

EQUATION : q(heat) = mass(gold) x specific heat capacity(gold) x change in temperature(solution)

= 225g x 0.129 J/g0C X (32.5 - 86)0C

=(-)1552.8 J where -ve sign indicates that heat is liberated.

2. Given mass of sample = 32.5 g

heat lost = (-) 328J

initial temperature 60 0C ,

Final emperature =16 0C

EQUATION : q(heat) = mass x specific heat capacity x change in temperature(solution)

SPECIFIC HEAT = heat (q)/ mass x change in temperature

= (-)328/32.5 x (16-60)

= 0.229 J/g 0C

3. GIVEN mass of metal piece = 1 kg =1000g

mass of water =100 g

initial temperature of water = 10 0C

final temperature of water =31.40C

initial temperature of metal = 520C

final temperature of METAL =31.40C

HEAT CAPACITY OF CALORIMETER =420 J/0C

specific heat of water =4.18 J/g0C

SPECIFIC HEAT OF METAL =?

q(metal) =-q (water)

specific heat of metal x mass of metal x temperature change of metal = (-)specific heat of water x mass of water x temperature change of water.

= specfic heat of metal x 1000g x (31.4-52) = (-)100 x 4.18 x (31.4-10)

specfic heat of metal  X (-) 20600 g 0C = (-) 8945.2 J

SPECIFIC HEAT OF METAL = 8945.2J/ 20600 g 0C

= 0.434 J/ g 0C