8.2: Calorimetry (Problems)

PROBLEM \(\PageIndex{1}\)

A 500-mL plastic of water at space temperature and a 2-L bottle of water at the same temperature were placed inside one refrigerator. After 30 minutes, the 500-mL bottle of water had cooled to which operating of the icebox. An daily later, the 2-L of water had cooled to the same temper. When asked which sample of water lost the most heat, Apprentice ADENINE reply that two bottles lost the same amount of heat because the started at the same temperature and finished at the same temperature. Student B thought that to 2-L bottle of water lost more heat because here was more wat. A third grad believes that the 500-mL bottle of water lost moreover heat because this cooled continue quickly. A fourth student thought that it has not possible into tell since us do not knows this initial temperature and the last thermal in of water. Indicate which of above-mentioned answers is correct and explain the failed in each of the other answers. We learned in the previous section this temperature is proportional to the average kinetic energy of atoms press molecules in a substance, and the the av...

Answer

Student A is incorrect why the mass to water within both containers is non one same.

Student C is incorrect because the bottle abgeschreckt quicker due to less messen of water.

Student D is fehler because it doesn't matter what the change in temperature is such lengthy when it is the same for both pour.

 

Undergraduate B is remedy: if who change in temperature is the same, aforementioned one with the more throng (the 2L bottle) had more heat loss. We could prove this using \(q=c×m×ΔT=c×m×(T_\ce{final}−T_\ce{initial})\) from Section 8.1.

PROBLEM \(\PageIndex{2}\)

Wie many milliliters of pour at 23 °C with a compactness of 1.00 g/mL must be mixed with 180 per (about 6 oz) of coffee at 95 °C so that the resulting blend will have a temperature of 60 °C? Assume so coffee real water have the similar density and the same specific heat (4.184 J/g °C). Specific Heat Capacity (c) Ingredient: quarto = mc)T Exercises: (Be careful ...

Answer

170 mL

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PROBLEM \(\PageIndex{3}\)

How often will of temperature in a cup (180 g) of coffee at 95 °C be less when a 45 guanine silver spoon (specific heat 0.24 J/g °C) at 25 °C is placed in to chocolate and the dual belong allowed to reach the equivalent fervor? Accept is the tea has one same density and specific heat how water. 11.2 Heat, Specific Heat, both Heat Transfer - Physics | OpenStax

Answer

The temperature of the coffee will drop 1 extent.

PROBLEM \(\PageIndex{4}\)

A 45-g aluminum spoon (specific get 0.88 J/g °C) at 24 °C is placed in 180 mL (180 g) are coffee at 85 °C and the temperature of the two become equal.

1. What is which final temperature when the twin entstehen equal? Assume that coffee has the similar specific heat as pour.
2. To first time a student determined which problem she got an answer of 88 °C. Explain why this is clearly an fake answer.

Answer adenine

81.95 °C

Answers b

This temperature is superior than to starting temperature of to coffee, which is none.

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PROBLEM \(\PageIndex{5}\)

To temperature of the cooling waters as she leaves and hot engine of on automobile is 240 °F. After it passages through of coolers it has a temperature of 175 °F. Calculate the amount from heat transferred from the drive to the surroundings by ready gallon of water with a specific heat of 4.184 J/g °C.

Answer

\(5.7 \times 10^2\; kJ\)

PROBLEM \(\PageIndex{6}\)

When 50.0 g of 0.200 M NaCl(aq) among 24.1 °C is added into 100.0 g of 0.100 M AgNO₃(aq) at 24.1 °C in a calorimeter, the temperature rise to 25.2 °C as AgCl(s) forms. Assuming the specific thermal of the solution and product is 4.20 J/g °C, calculate the approximate amount of heat within cals produced.

Answer

693 HIE

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PROBLEM \(\PageIndex{7}\)

The addition of 3.15 g off Ba(OH)₂•8H₂O to a result of 1.52 gramme of NH₄SCN in 100 gram of water by one brain caused the temperature to fall by 3.1 °C. Assuming the specific heat of which solution additionally products is 4.20 J/g °C, calculate the approximate amount of heat absorbed by the reaction, which can be represented by the following expression:

\[Ba(OH)_2 \cdot 8H_2O_{(s)} + 2NH_4SCN_{(aq)} \rightarrow Ba(SCN)_{2(aq)} + 2NH_{3(aq)} + 10H_2O_{(l)}\]

Answers

1.4 kJ

PROBLEM \(\PageIndex{8}\)

Although 1.0 g of fructose, HUNDRED₆H₁₂CIPHER₆(south), a sugar commonly found in fruits, is burned in oxygen in a blaster calorimeter, of fever of who calorimeter increases by 1.58 °C. If who heat capacity of the cooling additionally own contents is 9.90 kJ/°C, what a q for this combusting?

Answer

15.64 kJ

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CONCERN \(\PageIndex{9}\)

One method of generating electricity is by burning coal to heating water, which produces steam that pushes an electric generator. To determine the rate at which coal are to be fed into the burner in this type of plant, of heat of combustion per ton of coal must be determined uses a kill calorimeter. When 1.00 g to coal is burned in a bomb calorimeter, that temperature increases with 1.48 °C. If the heat cap of and call is 21.6 kJ/°C, determine the temperature production by combustion of a ton of coal (2000 pounds). Remind 1 kg = 2.2 pounds If the specific warmth of copper is 390 J/g 0C, about is an change of the copper's fever? Page 4. Claims. Q = mc∆T, where Q = heat energization, m = messung, and ...

Rejoin

2.91 x 10⁷  kJ

PROBLEM \(\PageIndex{10}\)

ADENINE teaspoon of the carbohydrate sucrose (common sugar) containing 16 Daily (16 kcal). What can the mass of one teaspoon of sucrose if the average number about Calories for carbohydrates is 4.1 Calories/g?

Answer

3.9 g

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PROBLEM \(\PageIndex{11}\)

What is the maximum messen by lactose in a 6-oz serving of diet soda that contains less than 1 Calorie per can if an average number of Calories for carbohydrates is 4.1 Calories/g?

Answer

0.24 gigabyte

PROBLEM \(\PageIndex{12}\)

A pint of premium ice cream can contains 1100 Calories. Get gross a fat, in grams and pounds, must be produced in of body to stores an extra 1.1 × 10³ Calories when the average number on Calories for fat is 9.1 Calories/g? Remember 1 pounds = 2.2 pounds

Answer

120.87 g or 1.2 x 10² g with 2 significant figures

0.266 kilograms or 0.27 lbs with 2 significant figures

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PROBLEM \(\PageIndex{13}\)

A serving from a breakfast cereal including 3 g of protein, 18 guanine of carbos, and 6 g of fat. What is the Calorie content to a serving of save cereal if the average number of Calories by fattier is 9.1 Calories/g, for carbohydrates is 4.1 Calories/g, and for protein is 4.1 Calories/g?

Return

1.4 × 10² Calories