Breaking glass is an example of a physical change because if you break it, it is still glass.
In the compound potassium nitrate (KNO3), the atoms within the nitrate ion are held together with COVALENT bonding, and the potassium ion and nitrate ion are held together by IONIC bonding.
A covalent bond, also called a molecular bond, is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs. Covalent bond is formed between two non-metals.
Ionic bonds form when one atom gives up one or more electrons to another atom. It is the complete transfer of valence electron(s) between oppositely charged atoms. Ionic bond is formed between metal (electropositive element) and non-metal(electronegative element)
In nitrate ions the Nitrogen (N) and Oxygen (O) both are non-metals and it involves the sharing of electron pairs between N and O atoms, so the bonding in Nitrate (
) ion is covalent bonding.
In potassium nitrate , Potassium (K) is a metal and Nitrate () ion is non-metal and it involves the complete transfer of valence electron between oppositely charged atoms (K+) and (). So the bonding between Potassium and Nitrate is Ionic bonding.
NOTE : Bonding between Non-metals is Covalent bonding.
Bonding between Metal and Non-metals is Ionic bonding.
<span>A physical change basically involves a change in physical properties. Some examples of physical properties include: texture, shape, size, color, volume, mass, weight, etc.
The water melting has changed the shape and therefore it's physical properties, but the chemical nature of the water has not been altered.
So that's why it's a physical change, and not a chemical change.</span>
Answer:
A chemical change because a temperature change occurred, the solid disappeared and a gas was produces
Explanation:
Magnesium reacts with hydrochloric acid releasing energy, and leading to the formation of magnesium chloride and hydrogen gas. This is represented by the equation below:
Mg₍s₎ + 2HCl₍aq)⇒ MgCl₂₍aq₎ + H₂₍g₎
To get the answer you use the Law of Raoult.
Raoult's law states that the decrease of the vapor pressure of a liquid is proportional to the molar fraction of the solute.
ΔP = Pa * Xa
Here Pa = 0.038 atm
And Xa = N a / (Na + Nb), where Na is number of moles of A and Nb is number of moles of b
Na = mass of urea / molar mass of urea = 60 g / (molar mass of CH4N2O)
molar mass of CH4N2O = 12 g/mol + 4*1g/mol + 2*14 g/mol + 16 g/mol = 60 g/mol
Na = 60 g / 60 g/mol = 1 mol
Nb = mass of water / molar mass of water = 180g / 18g/mol = 10 mol
Xa = 1 mol / (10 mol + 1 mol) = 1/11 =0.09091
ΔP = Pb * Xa = 0.038 atm * 0.09091 = 0.0035 atm
Then, the final vapor pressure of water is Pb - ΔP = 0.038atm - 0.0035atm = 0.035 atm.
Answer: 0.035 atm
