Question

В кастрюле массой 500г находится вода объемом 1 литр. Для нагревания воды сосуд ставят на спиртовую горелку. При сжигании этилового спирта в количестве 7 г кастрюля и вода нагреваются от температуры 20 градусов цельсия до температуры 60 градусов цельсия. Теплота сгорания топлива 26МДж/кг, теплоемкость воды 4,2КДж/(кг*градус цельсия). Определите удельную теплоемкость материала сосуда. Потерями теплоты в окружающую среду пренебречь

Answer 1

C1=26МДж/кг=26КДж/г
m(эт.спирта)=7г
M=0,5кг
Vводы=1л -> m=1кг
c2=4,2КДж/(кг*градус)
t2=60 градусов
t1=20 градусов
Q=c1*m(эт.спирта)
Q=M*c*(t2-t1)+m*c2*(t2-t1)=(t2-t1)(Mc+mc2)
c1*m(эт.спирта)=(t2-t1)(Mc+mc2)
c=(m(эт.спирта)*c1/(t2-t1)-m*c2)/M=700Дж/(кг*градус цельсия)

Answer 2

Calculation of Specific Heat Capacity of the Vessel Material

To determine the specific heat capacity of the vessel material, we need to use the equation:

Q = mcΔT

Where: - Q is the heat energy transferred to the water (in joules) - m is the mass of the water (in kilograms) - c is the specific heat capacity of the water (in joules per kilogram per degree Celsius) - ΔT is the change in temperature of the water (in degrees Celsius)

In this case, the heat energy transferred to the water is equal to the heat energy released by burning the ethanol:

Q = Q_ethanol = m_ethanol * ΔH_ethanol

Where: - Q_ethanol is the heat energy released by burning the ethanol (in joules) - m_ethanol is the mass of the ethanol burned (in kilograms) - ΔH_ethanol is the heat of combustion of ethanol (in joules per kilogram)

We are given that the mass of the ethanol burned is 7 grams, and the heat of combustion of ethanol is 26 MJ/kg.

Converting the mass of ethanol to kilograms: 7 grams = 0.007 kilograms

Converting the heat of combustion of ethanol to joules: 26 MJ/kg = 26,000,000 J/kg

Substituting the values into the equation: Q_ethanol = 0.007 kg * 26,000,000 J/kg = 182,000 J

Next, we can calculate the heat energy transferred to the water using the equation Q = mcΔT.

We are given that the initial temperature of the water is 20 degrees Celsius and the final temperature is 60 degrees Celsius.

Substituting the values into the equation: 182,000 J = m_water * c_water * (60 - 20)

We know the mass of the water is 500 grams, which is equal to 0.5 kilograms.

Substituting the values into the equation: 182,000 J = 0.5 kg * c_water * 40

Simplifying the equation: c_water = 182,000 J / (0.5 kg * 40)

Calculating the specific heat capacity of water: c_water = 910 J/kg°C

Therefore, the specific heat capacity of the vessel material is 910 J/kg°C.