1.) Air can be separated into its constituents such as oxygen, nitrogen etc.
2.) Air has a variable composition because at different places different amount of gases are present in air.
Answer:
A solid residue of limestone and some gypsum.
Explanation:
In step 2, some of the limestone and gypsum in the chalk dissolve in the water. When the mixture is filtered, the dissolved substances remain in the water. When the water is boiled off or evaporated, the solid substances remain behind.
Answer:
8×10^(-3) mol/L
Explanation:
The formula for finding the hydrogen ion concentration is...
[H⁺] = 10^-ph
[H⁺] = 10^(-2.1)
[H⁺] = 0.00794...mol/L = 8×10^(-3) mol/L
The answer is to 1 significant digit because the pH has one decimal place.
Answer: Mass of gas is 0.001 pounds.
Explanation:
Density is defined as the mass contained per unit volume.
Given : Mass of gas = ?
Density of gas = 
Volume of gas = 389 ml = 0.389 L (1L=1000ml)
Putting in the values we get:
(1g =0.002 lb)
Thus the mass of gas is 0.001 pounds.
