Question

If 0.015 mg Pb2+ were added to enough water to make exactly 1 L of solution,...

If 0.015 mg Pb2+ were added to enough water to make exactly 1 L of solution, the solution would be ____ M in Pb2+

7.2x10-3
1.5x10-5
7.2x10-8
1.5x10-8
7.2x10-5
7.2x103

2. The MCL for Pb2+ is 0.015 ppm this is equivalent to ______

15 mg/L
1.5 mg/L
0.15 mg/L
0.015 mg/L

0.0015 mg/L\]\

Homework Answers

Answer #1

Answer – 1) We are given, mass of Pb2+ = 0.015 mg, volume = 1.0 L

Molarity of solution = ?

We need to calculate the moles of Pb2+

We know,

1 mg = 0.001 g

So,0.015 mg = ?

= 1.5*10-5 g

moles of Pb2+ = 1.5*10-5 g / 207.2 g.mol-1

                       = 7.24*10-8 moles

We know molarity is

Molarity = moles / L

               = 7.24*10-8 moles / 1.0 L

                = 7.24*10-8 M

So, the solution would be 7.2*10-8 M in Pb2+

2) [Pb2+] = 0.015 ppm

We know

1 ppm = 1 mg/ L

So, 0.015 ppm = 0.015 mg/L

So, the MCL for Pb2+ is 0.015 ppm this is equivalent to 0.015 mg/L

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A 425 mg sample of a weak diprotic acid is dissolved in enough water to make...
A 425 mg sample of a weak diprotic acid is dissolved in enough water to make 275.0 ml of solution. The pH of this solution is 3.08. A saturated solution of calcium hydroxide (Ksp= 1.3 x 10-6) is prepared by adding excess calcium hydroxide to water and then removing the undissolved solid by filtration. Enough of the calcium hydroxide solution is added to the solution of the acid to reach the second equivalence point. The pH at the second equivalence...
A 425 mg sample of a weak diprotic acid is dissolved in enough water to make...
A 425 mg sample of a weak diprotic acid is dissolved in enough water to make 275.0 ml of solution. The pH of this solution is 3.08. A saturated solution of calcium hydroxide (Ksp= 1.3 x 10-6) is prepared by adding excess calcium hydroxide to water and then removing the undissolved solid by filtration. Enough of the calcium hydroxide solution is added to the solution of the acid to reach the second equivalence point. The pH at the second equivalence...
1. A standard solution of 100 ppm (100 mg / L) of an organic compound was...
1. A standard solution of 100 ppm (100 mg / L) of an organic compound was analyzed and this has a maximum absorption band at 270 nm. A calibration curve was prepared from which the following data were obtained: Conc. (Ppm) 1 1,5 2 3 4 Absorbance 0.1282   0.1940 0.2615 0.3995 0.5422        If 2 ml of an unknown solution of this compound are diluted to 50 ml, an absorbance of 0.425 is obtained. a. Calculate the concentration...
The following quantities of salts were added to water to make a 1-liter solution: 1X10-2 moles...
The following quantities of salts were added to water to make a 1-liter solution: 1X10-2 moles NaCl, 2X10-2 moles CaCl2, 4.166 grams BaCl2 1. What is the ionic strength of the solution? 2. What is the activity of the Cl species?
1. Isopropyl alcohol is mixed with water to produce a 35.0% (v/v) alcohol solution. How many...
1. Isopropyl alcohol is mixed with water to produce a 35.0% (v/v) alcohol solution. How many milliliters of each component are present in 745 mL of this solution? (Assume that volumes are additive.) 1A- _____ mL alcohol 1B-_____ mL water 2. Calculate the volume percent of solute in the following solutions. 2A- 16.9 mL of methyl alcohol in enough water to give 547 mL of solution. _____% 2B- 68.1 mL of ethylene glycol in enough water to give 229 mL...
1. How many grams of K2SO4 and how many grams of water are rwquired to make...
1. How many grams of K2SO4 and how many grams of water are rwquired to make 250.0g of a 0.2000 m solution? (Hint: First find m/m% K2SO4 in a 0.2000 m solution) 2. What is the mole fraction of K2SO4 in an 8.60% (m/v) aqueous solution of K2SO4? 3. If drinking water contains 1 ppm of fluoride, what is the molarity of F- in the water? How many grams of NaF would be required for a day's worth of water...
1. To 1.00 L of 0.0812 molar solution of acetic acid (ionization constant = 1.8 x...
1. To 1.00 L of 0.0812 molar solution of acetic acid (ionization constant = 1.8 x 10-5 ) few drops of concentrated HCl were added. These few drops contained 0.042 mol of HCl. Calculate the concentration of acetate ions after the addition of HCl. To simplify calculations, neglect the total volume change. a) 0.20 M b) 2.0 x 10-5 M c) 3.2 x 10-6 M d) None. My value is: ________ 2. Write ONLY NET IONIC equations that would occur...
1.) Indicate which aqueous solution has the lowest vapor pressure: a. 0.2 M MgCl2   b. 0.1...
1.) Indicate which aqueous solution has the lowest vapor pressure: a. 0.2 M MgCl2   b. 0.1 M MgCl2   c. 0.2 M NaCl d. 0.1 M KCl e. 0.1 M Na2CO3 2.) Indicate which aqueous solution has the fastest evaporation rate. a. 0.2 M MgCl2   b. 0.1 M MgCl2   c. 0.2 M NaCl d. 0.1 M KCl e. 0.1 M Na2CO3 3.) What is the molarity of a sucrose (C12H22O11) solution that produces an osmotic pressure of 2.65 atm at 25°C?...
3. In a saturated solution of the ionic compound sodium sulfate, Na3PO4 all of the water...
3. In a saturated solution of the ionic compound sodium sulfate, Na3PO4 all of the water molecules are involved in the hydration process. some solid Na3PO4 is present. all of the above the concentration of Na+ is three times the concentration of PO43-. 4. A solution contains 85 grams sucrose and 100. grams of water. What is the mass percent of the sucrose solution? 5. A solution contains only glycerol and fructose. There is ten times as much glycerol as...
In Part 1 of Lab 2 you will make and standardize a solution of NaOH(aq). Suppose...
In Part 1 of Lab 2 you will make and standardize a solution of NaOH(aq). Suppose in the lab you measure the solid NaOH and dissolve it into 100.0 mL of water. You then measure 0.2013 g of KHP (KC8H5O4, 204.22 g/mol) and place it in a clean, dry 100-mL beaker, and then dissolve the KHP in about 25 mL of water and add a couple of drops of phenolphthalein indicator. You titrate this with your NaOH(aq) solution and find...