its temperature by 6.2 °C? The How much heat must be addedto a 821 gsample ofgol

ID: 1046187 • Letter: I

Question

its temperature by 6.2 °C? The How much heat must be addedto a 821 gsample ofgold ton crease i specific heat of gold is 0.13 J/g'C. 4. 5. If 40.5 J of heat is added to a 15.4 g sample of silver, how much will the temperature increase by? The specific heat of silver is 0.235 J/g C. 6. A 2.50 g sample of zinc is heated, and then placed in a calorimeter containing 65.0 g of water. Temperature of water increases from 20.00 ? to 22.50 ?·The specific heat of zinc is 0.390 J/gC. What was the initial temperature of the zinc metal sample? (final temperatures of zinc and water are the same

Explanation / Answer

4. Q=m c ?T

Given m=8.21g Au

c=0.13J/g0C

?T=6.20C

Substitute the values in the above equation

=8.21g x 0.13J/g0C x 6.20C

=6.62J (cancel the units g and 0C)

5. Q=m c ?T

Given m=15.4g Ag

c=0.235J/g0C

?T=?0C

Q=40.5J

Therefore ?T=Q / mc

= 40.5J / (15.4g x 0.235J/g0C)

Therefore ?T= 11.20C (cancel the units J and g)

6. Let Ti be the initial temperature of Zinc.

H2O

Mass (g)

2.50

65.0

Specific heat J/g0C

0.390

4.184

?T (0C)

22.5 - Ti

22.5-20=2.5

Q=m c ?T

Qwater = - QZn

65.0g x 4.184 J/g0C x 2.50C= - [2.50g x 0.390 J/g0C x (22.5 - Ti)]

679.9= - [21.9375-0.975 Ti]

679.9+21.9375=0.975 Ti

Therefore Ti= 719.80C

H2O