Oops I left a part of the question out:

Question

Oops I left a part of the question out:

2. Mercury poisoning is a debilitating disease that is often fatal. In the human body, mercury reacts with essential enzymes, leading to irreversible inactivity of these enzymes. If the amount of mercury in a polluted lake is 215 ng of mercury / mL, what is the total mass in kilograms of mercury in the lake? (To simplify the math, imagine that the lake is a cylinder with a diameter of 0.67 miles and an average depth of 7.8 feet.)

Answer 1

You certainly did; however, I showed you how to work the problem. All you need to do now is to convert miles to cm and feet to cm, calculate the volume of the "cylinder" (pir^2depth) in cc, convert that to mL and plug in mL in the formula I gave you. Here is the link to my earlier response.

http://www.jiskha.com/display.cgi?id=1411524395

Post your work if you get stuck. Google can help you with the conversions.

Answer 2

To find the total mass of mercury in the lake, we need to calculate the volume of the lake first based on its dimensions, and then convert the given concentration from ng/mL to kg.

Let's break down the problem into steps:

Step 1: Calculate the volume of the lake.
To find the volume of the lake, we need to calculate the volume of the cylinder.

Given:
Diameter of the lake = 0.67 miles
Radius (r) of the lake = diameter/2 = 0.67/2 = 0.335 miles
Average depth of the lake = 7.8 feet

To convert the average depth from feet to miles, we need to divide it by the conversion factor:
1 mile = 5280 feet

Average depth (in miles) = 7.8 feet / 5280 feet/mile

Now we can calculate the volume of the lake's cylinder using the formula:
Volume = π * r^2 * h
where π is a constant, r is the radius, and h is the average depth.

Step 2: Convert concentration from ng/mL to kg.
Given:
Concentration = 215 ng/mL

To convert ng to kg, we need to divide by the conversion factor:
1 g = 1,000,000 ng
1 kg = 1000 g

Now that we have the volume of the lake and the concentration of mercury, we can calculate the total mass of mercury in the lake.

Step 3: Calculate the total mass of mercury.
Total mass of mercury = Volume * Concentration

Finally, let's plug in the values and calculate the answer.

Oops I left a part of the question out:

You certainly did; however, I showed you how to work the problem. All you need to do now is to convert miles to cm and feet to cm, calculate the volume of the "cylinder" (pi*r^2*depth) in cc, convert that to mL and plug in mL in the formula I gave you. Here is the link to my earlier response.

To find the total mass of mercury in the lake, we need to calculate the volume of the lake first based on its dimensions, and then convert the given concentration from ng/mL to kg.

You certainly did; however, I showed you how to work the problem. All you need to do now is to convert miles to cm and feet to cm, calculate the volume of the "cylinder" (pir^2depth) in cc, convert that to mL and plug in mL in the formula I gave you. Here is the link to my earlier response.