Question

You fill an ice tray with water at 25 degree celsius and place it into the freezer. Each cube has a volume of 30 mililiters (a mass of 30 g). Assume that heat is transferred from the water in each cube in the ice cube tray to the surrounding cold air in the freezer at a constant rate of 40 J/min. You can consider that the water (whether liquid or solid) in each cube is at uniform temperature. You can consider the heat capacity of the ice tray to be negligible. The pressure equals 0.101Mpa at all times.

A) calculate the temperature of the water/ice after 40 minutes of cooling

B) how many minutes wil it take for each cube to be frozen to a temperature of -10 degrees celsius

Answer #1

Heat removed in 40 min = 40 J/min x 40 min = 1600 J

Heat capacity of water = 4.187 J/g-K

Heat capacity of ice = 2.108 J/g-K

By heat balance,

Heat removed = Sensible heat removed from water till 0 C + latent heat of fusion + sensible heat removed from ice

Now,

Sensible heat removed from water till 0 C = mCp(T-0) = 30 x 4.187 x (25-0) = 3140.25 J > 1600 J

Therefore, till 40 min just the sensible heat is removed and hence the state is liquid.

By heat balance,

1600 = 30 x 4.187 (25-T2)

.: **T2 = 12.262 C**

B] By heat balance

Q = mCp_{water}(T1 - 0) +
+ mCp_{ice}(0-T2)

.: 40xt = 30x4.187x(25-0) + 334 + 30x2.108x[0-(-10)]

.: **t = 102.67 min**

An ice cube tray contains enough water at 28.0°C to make 18 ice
cubes that each has a mass of 30.0 g. The tray is placed in a
freezer that uses CF2Cl2 as a refrigerant. The heat of vaporiztion
of CF2Cl2 is 158 J/g. What mass of CF2Cl2 must be vaporized in the
refrigeration cycle to convert all the water at 28.0°C to ice at
–5.0°C? The heat capacities forH2O(s) and H2O(l) are 2.03 J/g·°C
and 4.18 J/g·°C, respectively, and...

You have 1.30 kg of water at 27.6 Degree Celsius in an insulated
container of negligible mass. You add 0.580 kg of ice that is
initially at -21.0 Degree Celsius. Assume no heat is lost to the
surroundings and the mixture eventually reaches thermal
equilibrium. If all of the ice has melted, What is the final
temperature (in Degree Celsius, round to 2 decimal places) of the
water in the container? Otherwise if some ice remains, what is the
mass...

If you pour whisky over ice, the ice will cool the drink, but it
will also dilute it. A solution is to use whisky stones. Suppose
Ernest pours 55.0 g of whisky at 25 ∘C room temperature, and then
adds three whisky stones to cool it. Each stone is a 32.0 gg
soapstone cube that is stored in the freezer at -11 ∘C. The
specific heat of soapstone is 980 J/kg⋅K; the specific heat of
whisky is 3400 J/kg⋅K.
What...

Consider two 35-gram ice cubes, each initially at -5°C. One is
dropped into a at container filled with 0.1 kg of liquid nitrogen
(initially the boiling point of nitrogen); the other cube is
dropped into a container filled with 1 kg of (liquid) water,
initially at 5°C. Assume that no heat is lost through either
container (or into the atmosphere)
a) Describe what happens to each ice cube (and why)
b) If (Lv)Nitrogen =48 kcal/kg, (LF)Nitrogen = 6.1 kcal/kg,
and...

Consider two 35-gram ice cubes, each initially at -5°C. One is
dropped into a at container filled with 0.1 kg of liquid nitrogen
(initially the boiling point of nitrogen); the other cube is
dropped into a container filled with 1 kg of (liquid) water,
initially at 5°C. Assume that no heat is lost through either
container (or into the atmosphere)
a) Describe what happens to each ice cube (and why)
b) If (Lv)Nitrogen =48 kcal/kg, (LF)Nitrogen = 6.1 kcal/kg,
and...

Consider two 35-gram ice cubes, each initially at -5°C. One is
dropped into a at container filled with 0.1 kg of liquid nitrogen
(initially the boiling point of nitrogen); the other cube is
dropped into a container filled with 1 kg of (liquid) water,
initially at 5°C. Assume that no heat is lost through either
container (or into the atmosphere).
1.Determine the final (equilibrium) temperature of the
icewater mixture.
2. Determine the phase (ie., liquid or solid) corresponding to
the...

Struggling, almost at the end of my class and I'm lost.
1. An ice chest at a beach party contains 12 cans of soda at
4.38 °C. Each can of soda has a mass of 0.35 kg and a specific heat
capacity of 3800 J/(kg C°). Someone adds a 8.54-kg watermelon at
29.8 °C to the chest. The specific heat capacity of watermelon is
nearly the same as that of water. Ignore the specific heat capacity
of the chest and...

You are working for a camping gear manufacturer and your boss
has asked you to design a new portable cooler. The portable cooler
will have the shape of a rectangular prism, with a height of 25 cm,
a width of 20 cm and a length of 35 cm. The walls of the cooler
will be composed of a thin inner liner (negligible resistance to
heat transfer), a gap containing water, and an outer insulating
wall having a thickness of 20...

As an eager scientist on a hot summer day you wish to determine
how much ice to buy to add to your cooler which is filled with 32
cans of soda which are warm at 82.9°F. Each can has a mass of 402 g
and ideally you want the temperature of the drinks to be 40.1°F. If
there is no heat lost by the cooler and ignoring any heat lost to
the soda containers, how much ice needs to be...

You want to cool 0.2 kg of coffee, initially at temperature Th =
80° C, with ice initially at Tc = 0° C. The specific heat of ice is
about 2108 J/kg K, and its latent heat of melting is about 334, 000
J/kg. You may take the specific heats of liquid water and coffee to
be the same: 4187 J/kg K.
A) Assume the coffee and ice form a closed system. You want them to
equilibrate at 40° C....

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 2 minutes ago

asked 2 minutes ago

asked 2 minutes ago

asked 17 minutes ago

asked 23 minutes ago

asked 27 minutes ago

asked 27 minutes ago

asked 27 minutes ago

asked 30 minutes ago

asked 45 minutes ago

asked 48 minutes ago

asked 1 hour ago