A 250.0 - ml aqueous solution contains 45.1 µg of a pesticide . Express the pesticide's concentration in weight percent , parts per million , and parts per billion .
It would be nice to have the density and to know the volume of water. Assuming 45.1 ug is so small and that the 250 mL of solution has a mass of 250 g, then % w/w = (mass solute/total mass)*100 = (45.1E-6g/250 g)*100.
Remember that percent w/w is parts per 100 (that's parts per 10^2). Multiply by 10,000(that's 10^4) to get ppm or by 10.000,000 (that's 10^7) to get ppb.
A quickie way I convert to ppm is 1 ppm = 1 mg/L which is a % w/v. That would be 45.1E-6 g or 0.0451 mg/250 mL = ? ppm
For dilute solutions ppm w/v and ppm w/w are essentially the same.
Oh, pesticide concentration! That's some serious business! Let me crunch a few numbers for you.
To express the pesticide's concentration in weight percent, we need to divide the mass of the pesticide by the total mass of the solution. So, given that you have 45.1 µg of pesticide in a 250.0 ml solution, we can convert µg to mg (milligrams) by dividing by 1000. This gives us a mass of 0.0451 mg.
Now, to calculate the weight percent, we divide the mass of the pesticide by the total mass of the solution and multiply by 100. In this case, the total mass of the solution is equal to its volume multiplied by the density of water, which is approximately 1 g/ml.
So, weight percent = (0.0451 mg / (250.0 ml * 1 g/ml)) * 100.
Now, let me fetch my calculator... *beep boop beep* Ah-ha, after performing the calculation, the pesticide's concentration in weight percent is approximately 0.01804%.
Moving on to parts per million (ppm), we can convert µg to mg (again divide by 1000) to get 0.0451 mg of pesticide. By definition, ppm is equal to the mass of the pesticide divided by the total mass of the solution and then multiplied by 1,000,000.
Therefore, ppm = (0.0451 mg / (250.0 ml * 1 g/ml)) * 1,000,000.
Oh, let me calculate that for you... *calculating sounds* And voila, the pesticide concentration is approximately 180.4 ppm.
Lastly, parts per billion (ppb) is one step further. We need to multiply our previous result (in ppm) by another 1000 to get ppb. Because ppm is parts per million, and billion is a thousand million.
So, the pesticide concentration in ppb is approximately 180,400 ppb. That's a lot of parts for a little pesticide!
Remember, these calculations are only as good as the accuracy of the given values. So, make sure you double-check your numbers and always have fun with chemistry!
To express the concentration of the pesticide in weight percent, parts per million (ppm), and parts per billion (ppb), we need to convert the mass of the pesticide to the desired units.
Step 1: Convert µg to grams:
1 µg = 1 × 10^(-6) g
Given that the solution contains 45.1 µg of the pesticide:
45.1 µg = 45.1 × 10^(-6) g = 4.51 × 10^(-5) g
Step 2: Calculate the weight percent concentration:
Weight percent = (mass of pesticide / total mass of the solution) × 100
Total mass of the solution = 250.0 ml = 250.0 g (assuming the density of the solution is approximately 1 g/ml, which is usually the case for water-based solutions)
Weight percent = (4.51 × 10^(-5) g / 250.0 g) × 100 = 1.80 × 10^(-5) %
Step 3: Calculate the parts per million (ppm) concentration:
Parts per million (ppm) = (mass of pesticide / total mass of the solution) × 10^6
Parts per million (ppm) = (4.51 × 10^(-5) g / 250.0 g) × 10^6 = 180.4 ppm
Step 4: Calculate the parts per billion (ppb) concentration:
Parts per billion (ppb) = (mass of pesticide / total mass of the solution) × 10^9
Parts per billion (ppb) = (4.51 × 10^(-5) g / 250.0 g) × 10^9 = 180,400 ppb
Therefore, the pesticide's concentration can be expressed as follows:
- Weight percent = 1.80 × 10^(-5) %
- Parts per million (ppm) = 180.4 ppm
- Parts per billion (ppb) = 180,400 ppb
To determine the pesticide's concentration in weight percent, parts per million (ppm), and parts per billion (ppb), first, we need to convert the mass of the pesticide from micrograms (µg) to grams (g).
Given that the solution contains 45.1 µg of the pesticide, we can convert it to grams by dividing by 1,000,000 (since there are 1,000,000 µg in a gram).
45.1 µg ÷ 1,000,000 = 0.0000451 g
Now, we can calculate the concentration in weight percent, parts per million, and parts per billion.
1. Concentration in weight percent:
Weight percent is calculated by dividing the weight of the solute (in grams) by the total weight of the solution (in grams) and multiplying by 100.
Weight Percent = (Weight of Solute ÷ Weight of Solution) × 100
In this case, the weight of the solute is 0.0000451 g, and the weight of the solution is 250.0 ml (which is equivalent to 250.0 g since the density of water is approximately 1 g/ml).
Weight Percent = (0.0000451 g ÷ 250.0 g) × 100 = 0.01804%
Therefore, the pesticide's concentration in weight percent is 0.01804%.
2. Concentration in parts per million (ppm):
Parts per million (ppm) is a ratio of the weight of the solute to the weight of the solution, multiplied by 1 million.
Parts per Million (ppm) = (Weight of Solute ÷ Weight of Solution) × 1,000,000
Using the same values as before:
Parts per Million (ppm) = (0.0000451 g ÷ 250.0 g) × 1,000,000 = 180.4 ppm
Therefore, the pesticide's concentration is 180.4 ppm.
3. Concentration in parts per billion (ppb):
Parts per billion (ppb) is a ratio of the weight of the solute to the weight of the solution, multiplied by 1 billion.
Parts per Billion (ppb) = (Weight of Solute ÷ Weight of Solution) × 1,000,000,000
Using the same values as before:
Parts per Billion (ppb) = (0.0000451 g ÷ 250.0 g) × 1,000,000,000 = 180,400 ppb
Therefore, the pesticide's concentration is 180,400 ppb.