# Problem Solving - Calculate the mass of steam condensed

• seongwei
In summary: So you can find the mass "m" of the pan.You are also given the mass (450g) and the temperature rise (103K) for the veges. So you can find the product c*m for the veges.You can also find the product c*m for the water (by using its given specific heat capacity).So three unknowns, c, m, and m. But you have two equations, one for energy and one for mass. You should be able to solve for two of the unknowns.For Q1, you are given the masses (of frozen veges and boiling water), and the initial and final temperatures. You are also given all the specific heat capacities and latent heats.
seongwei
Problem Solving -- Calculate the mass of steam condensed

1 ) A jet of steam at 100°C is directed into a hole in a large block of ice. After the steam has switched off, the condensed steam and melted ice are both a 0 degrees Celsius. The mass of water collected is 206 g. Calculate the mass of steam condensed.
Specific heat capacity of water is 4200 Jkg-1K-1
Specific heat capacity of ice is 2100 Jkg-1K-1
Latent heat of fusion is 330 X 1000 Jkg-1
Latent heat of vaporization is 2260 X 1000 Jkg-1

2 ) A mass of 450g of frozen vegetables is taken from a freezer at -20°C. The vegetables are immediately placed in saucepan containing 1100g of boiling water. The saucepan has a thermal capacity of 900J/K. The Final temperature of the saucepan,water and vegetables is 83°C.

a) calculate the specific heat capacity of the vegetables.

b ) the saucepan and its contents are then heated using a heater which provides 1200J of thermal energy each second. Determine how long it takes to bring the water back to its boiling point.

Can anyone solve these problems for me? Your help is very much appreciated.

Alas, it seems that you have misunderstood the purpose of these forums. Was it not clearly explained when you signed up?

This looks like homework? If so it should be in the Homework section where you will get help to solve them yourself.

Can anyone solve these problems for me?
We can - but you will learn more if you do it, even if it is not homework.
Show me how you would approach these problems and I'll help you over the rough bits.

Also - it is easier to explain stuff to you if I can see how you think.

Energy Lost by water = Energy gained by vege + saucepan

4200X1.1X(1oo-87) = 0.45XcX(83+20) + m(900)

Im stucked at here. I use the equation mcθ.

seongwei said:
Specific heat capacity of water is 4200 Jkg-1K-1
Specific heat capacity of ice is 2100 Jkg-1K-1
Latent heat of fusion is 330 X 1000 Jkg-1
Latent heat of vaporization is 2260 X 1000 Jkg-1

2 ) A mass of 450g of frozen vegetables is taken from a freezer at -20°C. The vegetables are immediately placed in saucepan containing 1100g of boiling water. The saucepan has a thermal capacity of 900J/K. The Final temperature of the saucepan,water and vegetables is 83°C.

a) calculate the specific heat capacity of the vegetables.

b ) the saucepan and its contents are then heated using a heater which provides 1200J of thermal energy each second. Determine how long it takes to bring the water back to its boiling point.

I have no idea for question 1. For question 2 : Energy Lost by water = Energy gained by vege + saucepan

4200X1.1X(1oo-87) = 0.45XcX(83+20) + m(900)

Im stucked at here. I use the equation mcθ.
Welcome to physics forums. Now that you have included some working, we can see where you may be having problems.

I think it is more likely that the saucepan and its hot water are initially at the same hot temperature, so you should revise the equation in words. What would it be in this case?

The capacity of the saucepan is quoted as Joules/degree, so it seems that they have already taken into account its mass. So your calculations won't specifically need the saucepan's mass.

seongwei said:
Energy Lost by water = Energy gained by vege + saucepan
That would be for Q2.

Doesn't the pan and the water start out at the same temperature?
Therefore, shouldn't energy flow from the pan to the veges as well?

4200X1.1X(1oo-87) = 0.45XcX(83+20) + m(900)
Note: you are given the thermal capacity "C"(=900J/K) for the pan.
Thermal capacity is related to the specific heat "c" by C=mc.

## 1. How do you calculate the mass of condensed steam?

To calculate the mass of condensed steam, you can use the equation: mass = volume x density. First, determine the volume of the steam, and then find the density of steam at that temperature and pressure. Multiply the two values to find the mass of condensed steam.

## 2. What is the density of steam?

The density of steam can vary depending on temperature and pressure. However, at standard atmospheric pressure (1 atm) and 100 degrees Celsius, the density of steam is approximately 0.598 kg/m^3.

## 3. How do you find the volume of steam?

The volume of steam can be found using the ideal gas law: V = nRT/P, where n is the number of moles of steam, R is the gas constant, T is the temperature in Kelvin, and P is the pressure. Alternatively, if the volume of the container holding the steam is known, that can also be used as the volume of the steam.

## 4. What is the ideal gas law?

The ideal gas law is a mathematical equation that describes the relationship between the pressure, volume, temperature, and number of moles of an ideal gas. It is written as PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.

## 5. Why is it important to calculate the mass of condensed steam?

Calculating the mass of condensed steam is important in many industrial applications, such as power plants and chemical processes. It helps determine the amount of energy required to condense the steam and the efficiency of the system. Additionally, the mass of condensed steam can also be used to calculate the amount of water that needs to be added to achieve a certain temperature or pressure in a system.

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