what is the concentration of the chloride ion when enough water is added to 12 grams of sodium chloride to make 4.0 Liters if solution?
(a) 0.025 M (b)0.05 M
(c) 0.1 M (d)0.2
12 g of NaCl is 12/58.5 = 0.205 moles
That gets dissolved into 4.0 l of H2O, resulting Na+ and Cl- concentrations of 0.051 moles/liter. The 0.05M answer is closest to that. They should not have dropped a significant figure.
Well, let me just dive into this question and see what floats to the surface.
To figure out the concentration of the chloride ion, we need to calculate the number of moles of sodium chloride first. So, let's grab our chemistry toolkit here and get to work.
The molar mass of sodium chloride is 58.44 grams/mol. Since we have 12 grams, we can divide that by the molar mass to find the number of moles: 12g / 58.44 g/mol ≈ 0.2056 moles.
Now, if we dissolve that amount of sodium chloride in 4.0 liters of water, we can take the number of moles and divide it by the volume in liters to find the concentration in moles per liter (Molarity). In this case, 0.2056 moles / 4.0 liters = 0.0514 M.
Ah, so it looks like we have a concentration of 0.0514 M for sodium chloride. But wait, the question asked for the concentration of the chloride ion specifically. Since sodium chloride breaks up into one sodium ion and one chloride ion when it dissolves, the concentration of the chloride ion is the same as the concentration of the sodium chloride.
So, adding a bit of sodium chloride and stirring things up will give us a concentration of 0.0514 M for the chloride ion. But hold on, I seem to have misplaced my options here. Let me just look under this pile of jokes and... Voila!
The answer is (b) 0.05 M.
To find the concentration of the chloride ion in the solution, we need to calculate the number of moles of sodium chloride (NaCl) and divide it by the volume of the solution.
Step 1: Calculate the molar mass of sodium chloride (NaCl).
The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl). The atomic mass of Na is 22.99 g/mol, and the atomic mass of Cl is 35.45 g/mol.
NaCl molar mass = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol
Step 2: Calculate the number of moles of NaCl.
To find the number of moles, divide the mass of NaCl by its molar mass.
Number of moles of NaCl = mass of NaCl / molar mass of NaCl
= 12 g / 58.44 g/mol
≈ 0.205 moles
Step 3: Calculate the concentration of chloride ion (Cl-) in moles per liter (M).
Concentration (in M) = moles of solute / volume of solution (in liters)
= 0.205 moles / 4.0 liters
= 0.05125 M
Step 4: Round the concentration to the appropriate number of significant figures.
The concentration of chloride ion in the solution, when enough water is added to 12 grams of sodium chloride to make 4.0 liters of solution, is approximately 0.051 M.
Therefore, the correct answer is (b) 0.05 M.
To find the concentration of the chloride ion, we need to first calculate the number of moles of sodium chloride (NaCl) in the solution and then divide it by the volume of the solution (in liters).
To calculate the number of moles of NaCl, we use the formula:
moles = mass / molar mass
The molar mass of NaCl is the sum of the atomic masses of sodium (Na) and chlorine (Cl), which are 23 g/mol and 35.5 g/mol respectively. Therefore, the molar mass of NaCl is 23 + 35.5 = 58.5 g/mol.
So, the number of moles of NaCl in 12 grams is:
moles = 12 g / 58.5 g/mol
Next, we need to convert the volume of the solution from liters to milliliters. Since 1 liter is equal to 1000 milliliters, 4 liters is equal to 4000 milliliters.
Finally, we can calculate the concentration of chloride ion in the solution using the formula:
concentration (in M) = moles / volume (in liters)
Let's do the calculation:
moles = 12 g / 58.5 g/mol = 0.205 moles
volume = 4.0 liters (given)
concentration = 0.205 moles / 4.0 liters = 0.05125 M
Rounding to the correct number of significant figures, the concentration of chloride ion is approximately 0.05 M.
Therefore, the correct answer is (b) 0.05 M.