The density of liquid water is 0.997 g/mL at 25 degrees Celsius.
a) Calculate the mass of 250.o mL (about a cupful) of water.
b) How many moles of water are in 250.0 mL of water? Use the result from letter a.
c) Calculate the volume that would be occupied by 2.000 mol of water at 25 degrees Celsius.
d) What mass of water is 2.000 mol of water?
a) mass = volume x density
b) moles = grams/molar mass
c) grams for 2.00 moles H2O = moles x molar mass. Then mass = volume x density and solve for volume.
d) See part c.
a) To calculate the mass of 250.0 mL of water, we can use the density of water.
The density of water is given as 0.997 g/mL. So, for every 1 mL of water, the mass is 0.997 grams.
To find the mass of 250.0 mL of water, we can multiply the volume (250.0 mL) by the density (0.997 g/mL):
Mass = Volume * Density
Mass = 250.0 mL * 0.997 g/mL
Mass = 249.25 grams
Therefore, the mass of 250.0 mL of water is 249.25 grams.
b) Now, let's calculate the number of moles of water in 250.0 mL using the mass calculated in part a.
To convert the mass of water in grams to moles, we need to know the molar mass of water.
The molar mass of water (H2O) is approximately 18.015 g/mol.
To calculate the number of moles, we can use the formula:
Number of Moles = Mass / Molar Mass
Number of Moles = 249.25 grams / 18.015 g/mol
Number of Moles = 13.829 moles
Therefore, there are approximately 13.829 moles of water in 250.0 mL.
c) To calculate the volume that would be occupied by 2.000 mol of water at 25 degrees Celsius, we can use the molar volume of water at standard temperature and pressure (STP).
The molar volume of water at STP is approximately 22.4 L/mol.
To convert this to mL, we can use the fact that 1 L = 1000 mL:
Molar Volume = 22.4 L/mol
Molar Volume = 22.4 * 1000 mL/mol
Molar Volume = 22400 mL/mol
Now, to calculate the volume of 2.000 mol of water, we can multiply the number of moles by the molar volume:
Volume = Number of Moles * Molar Volume
Volume = 2.000 mol * 22400 mL/mol
Volume = 44800 mL
Therefore, 2.000 mol of water would occupy a volume of 44800 mL at 25 degrees Celsius.
d) Finally, let's calculate the mass of 2.000 mol of water.
We can use the molar mass of water (18.015 g/mol) and the number of moles (2.000 mol) to find the mass:
Mass = Number of Moles * Molar Mass
Mass = 2.000 mol * 18.015 g/mol
Mass = 36.03 grams
Therefore, 2.000 mol of water has a mass of 36.03 grams.