Answer:
20ppm
Explanation:
parts per million are defined as the mass of solute in mg (In this case, mass of DDT) per kg of sample.
To solve this question we must find the mass of DDT in mg and the mass of sample in kg:
<em>Mass DDT:</em>
0.10g * (1000mg / 1g) = 100mg
<em>Mass sample:</em>
5000g * (1kg / 1000g) = 5kg
Parts per Million:
100mg / 5kg =
<h3>20ppm</h3>
ITS A SIMPLE.............................
FuFu Boys
Answer:
The International Date Line, established in 1884, passes through the mid-Pacific Ocean and roughly follows a 180 degrees longitude north-south line on the Earth. It is located halfway round the world from the prime meridian—the zero degrees longitude established in Greenwich, England, in 1852.
Answer is: 0,275 moles of oxygen are consumed.
Chemical reaction: 2Mg + O₂ → 2MgO.
n(Mg) = 0,550 mol.
n(O₂) = ?
from chemical reaction: n(Mg) : n(O₂) = 2 : 1.
0,550 mol : n(O₂) = 2 : 1.
2n(O₂) = 0,550 mol.
n(O₂) = 0,275 mol.
n - amount of substance.
Answer:

Explanation:
You must convert 30 % (m/v) to a molar concentration.
Assume 1 L of solution.
1. Mass of NaOH

2. Moles of NaOH

3. Molar concentration of NaOH

4. Volume of NaOH
Now that you know the concentration, you can use the dilution formula .

to calculate the volume of stock solution.
Data:
c₁ = 7.50 mol·L⁻¹; V₁ = ?
c₂ = 0.1 mol·L⁻¹; V₂ = 250 mL
Calculations:
(a) Convert millilitres to litres

(b) Calculate the volume of dilute solution

