25.00 mL of heavy water (D2O where D is a hydrogen with a neutron in its nucleus) at 20 degrees C was pipetted into a 37.234 g beaker. The final mass of the beaker was 64.859 9
a- what is the density of heavy water at 20 degrees C
b-The density of normal water (the hydrogens do not have neutrons) at 20 degrees C is 0.9982 g/mL. Calculate the density you would expect for heavy water by assuming the deuterium 2H or 2D is the same as normal hydrogen 1H when it is part of the water.
1.105
To solve this problem, we need to use the formula for density:
Density = Mass / Volume
Let's solve part a first:
a) To find the density of heavy water at 20 degrees C, we need to calculate the mass divided by the volume. The mass of the beaker is given as 37.234 g, and the initial volume of heavy water is given as 25.00 mL.
Density = mass / volume
Density = 37.234 g / 25.00 mL
Calculating the density:
Density = 1.48936 g/mL
Therefore, the density of heavy water at 20 degrees C is approximately 1.48936 g/mL.
Moving on to part b:
b) To calculate the expected density of heavy water by assuming deuterium is the same as normal hydrogen, we use the density of normal water at 20 degrees C, which is given as 0.9982 g/mL.
Since heavy water, D2O, has two deuterium atoms (2H) and one oxygen atom, we can consider the mass of the heavy water to be the sum of the masses of two deuterium atoms and one oxygen atom.
Using the atomic masses:
m(D) = 2.0141 g/mol (deuterium)
m(O) = 15.999 g/mol (oxygen)
The molar mass of heavy water (D2O) is:
2 * m(D) + m(O) = 2 * 2.0141 g/mol + 15.999 g/mol = 20.0272 g/mol
The density of heavy water can be calculated by dividing the molar mass by the volume (in mL), as we did before:
Density = molar mass / volume
Density = 20.0272 g/mol / 25.00 mL
Calculating the expected density:
Density = 0.80109 g/mL
Therefore, by assuming deuterium is the same as normal hydrogen, the expected density of heavy water at 20 degrees C is approximately 0.80109 g/mL.
To find the density of heavy water at 20 degrees Celsius, you need to use the formula:
Density = Mass / Volume
a) First, let's calculate the mass of heavy water using the information given:
Mass of heavy water = Final mass of the beaker - Initial mass of the beaker
= 64.8599 g - Initial mass of the beaker
b) To calculate the initial mass of the beaker, we need to consider that heavy water (D2O) has a density different from regular water (H2O). Since the beaker contains heavy water, we can find the mass of heavy water in the beaker using its volume and density:
Mass of heavy water in the beaker = Volume of heavy water in the beaker * Density of heavy water
Substituting the given values:
Volume of heavy water in the beaker = 25.00 mL
Density of heavy water = ? (to be calculated)
c) Next, let's calculate the volume of the heavy water using the pipetted volume:
Volume of heavy water = 25.00 mL
Now we have all the information needed to calculate the density of heavy water:
Density of heavy water = Mass of heavy water / Volume of heavy water
Substituting the calculated values, you can find the density.
b) To calculate the expected density of heavy water by assuming the deuterium (2D) is the same as normal hydrogen (1H), you can use the density of normal water (H2O) at 20 degrees Celsius, which is 0.9982 g/mL.
Since the atomic mass of deuterium (2H) is twice that of normal hydrogen (1H), we can assume that the density of heavy water will be approximately twice the density of normal water.
Expected density of heavy water = Density of normal water * 2
By substituting the given density of normal water, you can calculate the expected density of heavy water.
a.
mass D2O + beaker = 64.859
mass empty beaker.= -37.234
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.........mass D2O = ??
Then density = mass/volume
V = 25.00 in the problem.
I don't understand b.