Nope, it's a physical change. When ice melts it changes into liquid water, it's still water. Changes in which no new substances are formed are physical changes, hence this is a physical change.
<u>Answer:</u>
<u>For a:</u> The wavelength of light is 
<u>For b:</u> The light is getting absorbed
<u>Explanation:</u>
To calculate the wavelength of light, we use Rydberg's Equation:

Where,
= Wavelength of radiation
= Rydberg's Constant = 
= Higher energy level = 7
= Lower energy level = 3
Putting the values in above equation, we get:

Hence, the wavelength of light is 
There are two ways in which electrons can transition between energy levels:
- <u>Absorption spectra:</u> This type of spectra is seen when an electron jumps from lower energy level to higher energy level. In this process, energy is absorbed.
- <u>Emission spectra:</u> This type of spectra is seen when an electron jumps from higher energy level to lower energy level. In this process, energy is released in the form of photons.
As, the electron jumps from lower energy level to higher energy level. The wavelength is getting absorbed.
<span>b.mixtures are made up of more than one component</span>
The balanced chemical reaction:
K2SO4 + O2 = 2KO2 + SO2
Assuming that the reaction is complete, all of the potassium sulfate is consumed. We relate the substances using the chemical reaction. We calculate as follows:
7.20 g K2SO4 ( 1 mol / 174.26 g) ( 1 mol O2 / 1 mol K2SO4 ) ( 32 g / 1 mol ) = 1.32 g O2 consumed in the reaction.
Answer:
The Correct increasing order of solubility is O2 < Br2 < LiCl < Methanol (CH3OH)
Explanation:
Solubility of compounds or molecules are solely dependent on its inter molecular forces or bonding present in them.
Molecules with Hydrogen bonding usually very soluble in water. Ionic compounds are also very soluble in water because they form ions in solutions. Molecules that possess van der waal forces are usually insoluble in water because they are non-polar.
- O2 (oxygen gas) and Br2 (bromine gas) have van der waal forces in them. Van der waal forces are stronger in Br2 (bromine gas) than O2 (oxygen gas) because Br2 has more number of electrons.
- LiCl is ionic in nature which makes it dissolve in water readily. it easily forms its ions (Li+ and Cl- ) in solutions.
- Methanol (CH3OH) has the highest solubility in water compared to LiCl, Br2 and O2 because it contains Hydrogen bonding which is strongest of all inter molecular forces.