Answer: Option (D) is the correct answer.
Explanation:
- A pure substance is defined as the substance that is made up of only one type of atom or only one type of molecule.
For example,
is a molecule and it is a pure substance.
Also, substances that contain two or more different element which are chemically combined in a fixed ratio by mass are known as compounds. They are also pure substances.
A pure substance can only be separated by a chemical method and not by any physical method.
- A heterogeneous mixture is defined as the mixture which contains non-uniform composition of solute particles into the solution.
For example, mud dissolved in water.
It is not necessary that two or more substance present in a heterogeneous mixture should be of same phase.
Also, it is not necessary that combination of a liquid and a solid always results in a heterogeneous mixture.
If the solid is able to dissolve completely into the liquid then it will result in a homogeneous mixture.
- Whereas a homogeneous mixture is defined as the mixture which contains uniform distribution of solute particles into the solvent.
For example, salt dissolved in water is a homogeneous mixture.
Thus, we can conclude that the statement composition is uniform throughout a homogeneous mixture, is correct.
Answer:
b. It exists in three different states at normal conditions in the Earth's atmosphere
Explanation:=
Snow, rain and water vapour can exist at normal conditions in the Earth's atmosphere.
a. is wrong. Only hydrogen and helium can escape Earth's atmosphere in significant amounts.
c. is wrong. The molecules of every substance are in motion even when it is solid.
d. is wrong. Other substances can form from a wide range of chemical processes.
e. is wrong. All substances expand when they become a gas.
CS2 + 3O2 = CO2 + 2SO2
1 mole of CS2 gives 1 mole of CO2
12 + 2(32) = 76g of CS2 yields 44 g of CO2
Theoretically 1 g of CS2 yields 44/76 g CO2
Therefore 50 g CS2 should yield 50*44 / 76 = 28.95 g
So % yield = 103.6 % ( which is not possible because you can't create matter from nothing).
The 30g cannot be right . This is experimental err.