Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012% Pb by mass. How much of the water in milliliters contains 145 mg of Pb? (Assume that the density of the solution is 1.0g/mL.)
Oh, lead, the not-so-shiny metal! Let's break it down.
First, let's find the mass of the water in the sample. Since we know the sample contains 0.0012% Pb by mass, we can assume that the remaining 99.9988% is water. So, we'll calculate the mass of the water using the mass of lead:
Mass of lead (Pb) = 145 mg = 0.145 g
Now, let's figure out the total mass of the sample:
Total mass of sample = Mass of lead (Pb) / (Percentage of Pb in the sample)
= 0.145 g / (0.0012/100)
≈ 120.8333 g
Next, we need to convert the mass of the sample to volume using the density of the solution:
Volume of the sample = Mass of the sample / Density of the solution
= 120.8333 g / 1.0 g/mL
≈ 120.8333 mL
So, approximately 120.8333 milliliters of water contains 145 milligrams of lead.
To solve this problem, we can use the concept of percent composition by mass. The percent composition by mass represents the mass of the solute (in this case, Pb) compared to the total mass of the solution (water + Pb).
Let's start by calculating the mass of the Pb in the water sample:
Mass of Pb = Percent composition by mass × Mass of the solution
Mass of Pb = 0.0012% × Mass of the solution (1)
Next, we can convert the mass of Pb to milligrams since we are given the amount of Pb in milligrams:
Mass of Pb (in mg) = 145 mg (2)
Now we can equate equations (1) and (2) to solve for the mass of the solution:
0.0012% × Mass of the solution = 145 mg
Dividing both sides of the equation by 0.0012%:
Mass of the solution = (145 mg) / (0.0012%)
Now we need to convert the mass of the solution to volume using the density provided. The density of the solution is given as 1.0 g/mL, which means that 1 mL of the solution has a mass of 1.0 g.
To find the volume in milliliters, we need to convert grams to milliliters:
Volume of the solution (in mL) = Mass of the solution (in g)
Substituting the values:
Volume of the solution (in mL) = (Mass of the solution) / (Density of the solution)
Now, we can substitute the mass of the solution we obtained earlier:
Volume of the solution (in mL) = [(145 mg) / (0.0012%)] / (1.0 g/mL)
Simplifying the expression:
Volume of the solution (in mL) = (145 mg) / (0.000012)
Calculating the value:
Volume of the solution (in mL) = 12,083.33 mL
Therefore, approximately 12,083.33 mL of the water sample contains 145 mg of Pb.
To solve this problem, we can use the concept of mass percent and the density of the solution.
First, we need to calculate the mass of the water sample containing 145 mg of Pb.
Given that the Pb-contaminated water sample contains 0.0012% Pb by mass, we can write this as:
0.0012% = 0.0012/100 = 0.000012
So, the mass of Pb in the water sample is:
0.000012 * mass of the water sample = 145 mg
Now, we can calculate the mass of the water sample:
mass of the water sample = 145 mg / 0.000012
Next, we need to convert the mass of the water sample into volume using the density of the solution.
Given that the density of the solution is 1.0 g/mL, we can write:
volume of the water sample = mass of the water sample / density of the solution
Now, let's substitute the values into the equation:
volume of the water sample = (145 mg / 0.000012) / 1.0 g/mL
Simplifying the expression:
volume of the water sample = 12083333.33 mL
Therefore, approximately 12,083,333.33 milliliters of water contain 145 mg of Pb.
So from density we know that
.0012 g/100 mL
Converting g into mg
0.0012% = 0.0012 g/100 ml water, or 1.2 mg
so for 145 mg, you need
145mg Pb *100mL/1.2mg Pb = 12083 ml water or 12.083 L of water