Answer:
Tests for gases
Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.
Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.
Oxygen. A glowing wooden splint relights in a test tube of oxygen.
hope it will help
Answer : The volume of gas occupy at 
is, 1.25 L
Explanation :
Charles' Law : It states that volume of the gas is directly proportional to the temperature of the gas at constant pressure and number of moles.
Mathematically,
where,
are the initial volume and temperature of the gas.
are the final volume and temperature of the gas.
We are given:
Putting values in above equation, we get:
Therefore, the volume of gas occupy at is, 1.25 L
Answer:
E) Intramolecular bond angles change
Explanation:
Infrared Radiation:
IR is electromagnetic radiations. The wavelength i.e. 700nm to 1000 mm of infrared is longer than invisible light and Its frequency is lower than light, that's why it is invisible to light.
- When IR radiation strike the molecule it absorbed by this molecule.
- This radiation used to identify and study chemicals.
- Infrared radiation interact with intra-bonds of the molecule.
- Bonds in the molecules have vibrational translational and rotational movements
- Due to these vibration, rotation and translation movement it absorb a radiation of specific frequency and wavelength
- These movements of bond are very small and absorbs radiations of very low frequency
- So when Infrared light or radiation absorbed the intra-bonds of the molecule get affected and angles of these bonds changes.
- As the frequency of the absorbed radiation matches the frequency of the bond that vibrates.
So
The correct option is option E
E) Intramolecular bond angles change
* Note:
it couldn't be option A as the frequency of IR is not enough to rotate a whole molecule
It Couldn't be option B as IR rations are electromagnetic radiation of longer wave length so it one can not see it with light so how it will glow a molecule
It also not could be the option C as for the excitation of electrons require much higher energy.
It also not the option D as nuclear magnetic spin is associated with nuclear magnetic radiation that are much different from IR.
Answer: a. two substances present; two phases present : Heterogeneous mixture
b. two substances present; one phase present
: Homogeneous mixture
c. one substance present; one phase present
: pure substance.
d. one substance present; two phases present: Heterogeneous mixture
Explanation:
A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.
Mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.
Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium.
Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium.
Gravity is a force which tries to pull two objects toward each other. Anything which has mass also has a gravitational pull. The more massive an object is, the stronger its gravitational pull is. Earth's gravity is what keeps you on the ground and what causes objects to fall.
