The heat of vaporization of ammonia is 23.4 kj/moles. How much heat is required to vaporize 1.00kg of ammonia? How many grams of water at 0 degree celcius could be frozen to ice at 0 degree celcius by evaporation of this Amount of ammonia?
I got the kj by doing the layout 1,000 g nh3 x 1/17.0 g/mol nh3 x -23.4/1 mol nh3 = 1.37 x 10 ^3 kj nh3 its the second part to find the grams is the problem for me. Please help
The heat required to vaporize 1.00 kg of ammonia is 23,400 kJ. To find the number of grams of water that could be frozen to ice by the evaporation of this amount of ammonia, we need to calculate the amount of heat released by the evaporation of 1.00 kg of ammonia. This can be done by using the equation Q = m x c x ΔT, where Q is the heat released, m is the mass of the substance, c is the specific heat capacity of the substance, and ΔT is the change in temperature. For water, the specific heat capacity is 4.18 J/g°C.
Therefore, the amount of heat released by the evaporation of 1.00 kg of ammonia is 23,400 kJ. This amount of heat can be used to freeze 1.00 kg x 4.18 J/g°C x 0°C = 4,180 g of water at 0°C.
To find the amount of heat required to vaporize 1.00 kg of ammonia, you can use the molar mass of ammonia (NH3), which is approximately 17.0 g/mol.
1. Firstly, convert the given mass of ammonia to moles:
1.00 kg NH3 × (1000 g/1 kg) × (1 mol/17.0 g) = 58.82 mol NH3
2. Now, use the molar heat of vaporization of ammonia:
58.82 mol NH3 × (-23.4 kJ/mol) = -1373 kJ NH3 (Note: the negative sign indicates heat is absorbed)
Therefore, the heat required to vaporize 1.00 kg of ammonia is approximately 1373 kJ.
To determine the number of grams of water that can be frozen to ice by the evaporation of this amount of ammonia, we need to consider the heat released during the condensation process. The heat released is equal to the heat absorbed during vaporization.
The specific heat of fusion for water is 334 J/g and the molar heat of vaporization of ammonia is 23.4 kJ/mol (which can be converted to J/g using the molar mass of ammonia).
1. Calculate the heat released by the condensation of ammonia:
-1373 kJ NH3 × (1000 J/1 kJ) = -1373000 J NH3
2. Convert the heat released to grams of water using the heat of fusion:
-1373000 J NH3 × (1 g/334 J) = -4110 g NH3 (Note: the negative sign indicates heat is released)
Therefore, by the evaporation of this amount of ammonia, approximately 4110 grams of water at 0 degrees Celsius could be frozen to ice at 0 degrees Celsius.
To find the heat required to vaporize 1.00 kg of ammonia, you correctly used the heat of vaporization value (23.4 kJ/mol) to calculate the heat in kJ for 1.000 g of ammonia.
Now, to find how many grams of water can be frozen to ice by the evaporation of this amount of ammonia, you need to consider the heat transfer between the ammonia and the water.
The heat released during the condensation of the vaporized ammonia will be equal to the heat absorbed during the freezing of water. This is because the heat of vaporization of ammonia (heat released) is equal to the heat of fusion of water (heat absorbed) when both happen at the same temperature (0 °C in this case).
The heat of fusion of water is approximately 333.55 kJ/kg. To find the amount of water that can be frozen by the evaporation of this amount of ammonia, you can use the following calculation:
Amount of water frozen = Heat released by ammonia / Heat of fusion of water
First, convert the heat released by ammonia to joules (J):
1.37 x 10^3 kJ = 1.37 x 10^3 x 10^3 J = 1.37 x 10^6 J
Now, divide the heat released by ammonia in joules by the heat of fusion of water in kJ/kg:
Amount of water frozen = (1.37 x 10^6 J) / (333.55 kJ/kg)
To get the answer in grams, you need to know the density of water. The density of water at 0 °C is approximately 1 g/cm^3 or 1000 kg/m^3.
Amount of water frozen (in grams) = Amount of water frozen (in kg) x Density of water
To convert the amount of water frozen from kilograms to grams, divide by 1000:
Amount of water frozen (in grams) = (Amount of water frozen (in kg) / 1000) x Density of water
Substitute the value of the heat released by ammonia:
Amount of water frozen (in grams) = (1.37 x 10^6) / (333.55 x 1000) x 1000
Perform the calculation to find the amount of water that can be frozen by the evaporation of this amount of ammonia.