a solution containing 30 g of nh3 in 70 g of water has a density of 0.882 g/ml. what is the molarity and molality
illustrate and calculate the distance each of the following gases would meet on a 12 foot tube: gas A has a molecular weight of 288grams/mole: gas B has a molecular weight of 56 grams/mole
20.1
Molarity 20.1 M
Molality 24.9 m
To find the molarity and molality of the solution, we need to first calculate the moles of NH3 and water present in the solution.
Step 1: Calculate the moles of NH3
We know that the mass of NH3 is 30 g, and its molar mass is 17.03 g/mol.
Number of moles of NH3 = Mass of NH3 / Molar mass of NH3
= 30 g / 17.03 g/mol
≈ 1.7606 mol
Step 2: Calculate the moles of water
We know that the mass of water is 70 g, and its molar mass is 18.02 g/mol.
Number of moles of water = Mass of water / Molar mass of water
= 70 g / 18.02 g/mol
≈ 3.884 mol
Step 3: Calculate the total volume of the solution
The density of the solution is given as 0.882 g/ml. Since density is defined as mass/volume, we can rearrange the equation to solve for volume.
Volume of the solution = Mass of the solution / Density of the solution
= (30 g + 70 g) / 0.882 g/ml
≈ 113.378 ml
Step 4: Calculate the molarity
Molarity is defined as the number of moles of solute (NH3) divided by the volume of the solution in liters.
Molarity (M) = Number of moles of NH3 / Volume of solution (in L)
= 1.7606 mol / (113.378 ml / 1000)
≈ 15.54 M
Step 5: Calculate the molality
Molality is defined as the number of moles of solute (NH3) divided by the mass of the solvent (water) in kilograms.
Molality (m) = Number of moles of NH3 / Mass of water (in kg)
= 1.7606 mol / (70 g / 1000)
≈ 25.151 mol/kg
Therefore, the molarity of the solution is approximately 15.54 M and the molality is approximately 25.151 mol/kg.
30 g NH3 is how many moles? moles = g/molar mass.
70g H2O is how many kg? 0.070?
Then molality = moles/kg solvent.
For molarity, you want M = moles/L soln.
You have moles already.
The solution has a mass of 100 g (70 gH2O + 30 g NH3). Calculate volume from density and mass.
Then M = moles/L