A farmer applies 1400.0 kg of a fertilizer that contains 10.0% nitrogen to his fields each year. fifteen (15.0%) percent of the fertilizer washes into a river that runs through the farm.
If the river flows at an average rate of 0.410 cubic feet per second, what is the additional concentration of nitrogen ( expressed in milligrams of nitrogen per liter) in the river water due to the farmer's fertilizer?
I'm so sorry for bothering you, but the answer still wrong. It says that this is similar to the amount of fertilizer in the river water, but the amount of nitrogen will be less. So, what percent of the total mass of the fertilizer is nitrogen?
Thanks,
1. Determine the mass of nitrogen that washes into the river each year, in milligrams.
( Multiply the mass of fertilizer by both percentages. )
2. Determine the volume of river that flows through the farm each year, in litres.
( Convert cubic feet to litres, multiply by the number of seconds in a year. )
3. Divide and conquer.
I know that. I already used these steps, but the answer was wrong.
1: 1400.0 * 10^6 * 0.100 * 0.150 = 2.10E7 mg
2: 0.410 * 28.32 * 3.154E7 = 3.66E8 L
3: 0.574 mg/L
To find the additional concentration of nitrogen in the river water due to the farmer's fertilizer, we need to calculate the amount of nitrogen that washes into the river and then convert it to milligrams per liter.
First, let's find the amount of nitrogen in the fertilizer:
10% of 1400.0 kg = 0.10 * 1400.0 kg = 140 kg
Next, we need to find the amount of nitrogen that washes into the river:
15% of 140 kg = 0.15 * 140 kg = 21 kg
Now, let's convert the mass of nitrogen to milligrams:
1 kg = 1000 g
1 g = 1000 mg
21 kg = 21,000 g = 21,000,000 mg
To calculate the concentration of nitrogen in the river water, we need to know the volume of water that flows through the river in a given time.
The formula to calculate the concentration of a substance in a solution is:
Concentration = Mass of Substance / Volume of Solution
To find the volume of water between two points in the river, you'll need to know the distance between the two points and the cross-sectional area of the river at those points. Multiplying the distance by the cross-sectional area will give you the volume.
Since you have provided the average rate of flow of the river, 0.410 cubic feet per second, you'll also need to convert this to liters.
1 cubic foot = 28.32 liters
So, 0.410 cubic feet = 0.410 * 28.32 liters = 11.5292 liters
Now, we can calculate the concentration of nitrogen in the river water:
Concentration = 21,000,000 mg / 11.5292 liters
Calculating this, we find:
Concentration ≈ 1,822,612.57 mg/L
Therefore, the additional concentration of nitrogen in the river water due to the farmer's fertilizer is approximately 1,822,612.57 milligrams of nitrogen per liter.