Question

A coffee-cup calorimeter contains 130.0 g of water at 25.3 ∘C . A 124.0-g block of copper metal is heated to 100.4 ∘C by putting it in a beaker of boiling water. The specific heat of Cu(s) is 0.385 J/g⋅K . The Cu is added to the calorimeter, and after a time the contents of the cup reach a constant temperature of 30.3 ∘C .

Part A

Determine the amount of heat, in J , lost by the copper block. (3350 J)

Part B Determine the amount of heat gained by the water. The specific heat of water is 4.18 J/g⋅K . (2720 J) Part C The difference between your answers for (a) and (b) is due to heat loss through the Styrofoam® cups and the heat necessary to raise the temperature of the inner wall of the apparatus. The heat capacity of the calorimeter is the amount of heat necessary to raise the temperature of the apparatus (the cups and the stopper) by 1 K . Calculate the heat capacity of the calorimeter in J/K . Express your answer using two significant figures. Part D What would be the final temperature of the system if all the heat lost by the copper block were absorbed by the water in the calorimeter? |

Answer #1

**Q = mc∆T**

*Q* = heat energy (Joules, J),
*m* = mass of a substance (kg)

*c* = specific heat (units
J/kg∙K), *∆* is a symbol meaning "the change in"

*∆T* = change in temperature
(Kelvins, K)

Part A

heat, in J , lost by the copper block

Q = 124g x 0.385 J/g⋅K x ( 100.4 ∘C -30.3 ∘C)

Q =3346.574 Joules

Part B

The amount of heat gained by the water

Q = 130g x 4.184 J/g⋅K x ( 30.3 ∘C -25.3 ∘C)

Q =2719.6Joules

Part C

heat capacity of the calorimeter 3346.574 Joules - 2719.6 Joules / 5 ∘C = 125.3948 ∘C

we can use either ∘C or kelvin

Part D

Heat lost by copper = Heat gained by water

124g x 0.385 J/g⋅K x ( 100.4 ∘C - X ∘C) = 130g x 4.184 J/g⋅K x ( X -25.3 ∘C)

4793.096 - 47.74 X = 543.92 X -13761.176

18554.272 = 591.66 X

**X = 31.359 ∘C**

**Hence final temperature will
be 31.359 ∘C**

A calorimeter contains 75.0 g of water at an initial temperature
of 25.2 °C. 151.28 g of copper metal at a temperature of 95.5 °C
was placed in the calorimeter. The equilibrium temperature was 36.2
°C. The molar heat capacity of water is 75.4 J / mol °C. Determine
the molar heat capacity of the copper.

Calorimetry Problem: Show your work neatly and methodically.
Include the sign associated with ΔH.
1. When a 6.55 gram sample of solid sodium hydroxide dissolves
in 115.00 grams of water in a coffee-cup calorimeter, the
temperature rises from 21.6°C to 38.7°C. Calculate ΔH, in kJ/mole
NaOH, for the solution process. NaOH(s) Na1+(aq) + OH1- (aq) The
specific heat of the solution is 4.18 J/g °C. 3.
2, A 2.600 gram sample of phenol, C6H5OH, was burned in a bomb...

A student wishes to determine the heat capacity of a coffee-cup
calorimeter. After she mixes 95.8 g of water at 62°C with 95.8 g of
water, already in the calorimeter, at 18.2°C, the final temperature
of the water is 35.0°C. Calculate the heat capacity of the
calorimeter in J/K. Use 4.184 J/g°C as the specific heat of
water.

A coffee-cup calorimeter initially contains 125 g water at 24.2
degrees celsius. Ammonium Nitrate (10.5 g), also at 24.2 degree
celsius, is added to the water, and after the ammonium nitrate
dissolves, the final temperature is 18.3 degrees celsius.What is
the heat of solution of ammonium nitrate in kj/mol? Assume that the
specific heat capacity of the solution is 4.18 J/Cg and that no
heat is transferred to the surrounds or to the calorimeter.

In a coffee-cup calorimeter, 130.0 mL of 1.0 M NaOH and 130.0 mL
of 1.0 M HCl are mixed. Both solutions were originally at 26.8°C.
After the reaction, the final temperature is 33.5°C. Assuming that
all the solutions have a density of 1.0 g/cm and a specific heat
capacity of 4.18 J/°C ⋅ g, calculate the enthalpy change for the
neutralization of HCl by NaOH. Assume that no heat is lost to the
surroundings or to the calorimeter.
Enthalpy change...

When 10.0 g KOH is dissolved in 100.0 g of water in a coffee-cup
calorimeter, the temperature rises from 25.18 ˚C to 47.53 ˚C.
Calculate the ∆Hrxn for the dissolution process. Assume that the
solution has a specific heat capacity of 4.184 J/gK

An insulated aluminum calorimeter vessel of 150 g mass contains
300 g of liquid nitrogen boiling at 77 K. A metal block at an
initial temperature of 303 K is dropped into the liquid nitrogen.
It boils away 15.8 g of nitrogen in reaching thermal equilibrium.
The block is then withdrawn from the nitrogen and quickly
transferred to a second insulated copper calorimeter vessel of 200
g mass containing 500 g of water at 30.1 degrees celsius. The block
coolds...

Steam at 100°C is condensed into
a 38.0 g copper calorimeter cup containing 260 g of water at 27.0°C. Determine the amount of steam (in
g) needed for the system to reach a final temperature of
56.0°C. The specific heat of copper is
387 J/(kg
· °C).

The aluminum cup inside your calorimeter weighs 39.96 g. You add
49.96 g of ice cold water to the calorimeter. You measure the
temperature of the calorimeter to be 0.5oC just before your next
addition. You then add 50.44 g of hot water and a 50.10 g metal
object, all having an initial temperature of 69.5oC. After the
calorimeter reaches thermal equilibrium, the final temperature is
measured to be 36.1oC. Assume that: the calorimeter is completely
insulated the heat capacity...

The aluminum cup inside your calorimeter weighs 40.85 g. You add
49.81 g of water and 3.03 g of KCl to the calorimeter. The initial
temperature is 20.1oC, and the final temperature is 16.9oC. What is
the heat of dissolution for the amounts of salt added, in units of
J? Assume that: the calorimeter is completely insulated the heat
capacity of the empty calorimeter is the heat capacity of the
aluminum cup. the mass of KCl added is small enough...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 13 minutes ago

asked 17 minutes ago

asked 20 minutes ago

asked 25 minutes ago

asked 39 minutes ago

asked 41 minutes ago

asked 41 minutes ago

asked 1 hour ago

asked 1 hour ago

asked 1 hour ago

asked 2 hours ago

asked 2 hours ago