Answer:
D. Sweat evaporates from your skin
Explanation:
A physical change is a reversible process, no new substance is formed. A physical change does not affect the chemical composition of a substance.
Sweat evaporation from the skin is a physical change, because the change that occur is merely a change of state, Liquid to Gaseous state, no new substance is formed.
Answer:
d) Ni < Co < Fe < Zn < Al
Explanation:
electronegativity of Aluminium 1.6
electronegativity of Zinc 1.7
electronegativity of iron 1. 83
electronegativity of Cobalt 1.88
electronegativity of Nickel 1.91
As the electronegativity of aluminium is lower as compared to other, so it will have high tendency to easily lose electron and that is why Aluminium is more reactive than the other mentioned
First, let's write the chemical formula for each of the substances mentioned in the problem.
Strontium Chloride: SrCl₂
Lithium Phosphate: Li₃PO₄
Strontium Phosphate: Sr₃(PO₄)₂
Lithium Chloride: LiCl
So, the balanced chemical reaction is:
<em>3 SrCl₂ (aq) + 2 Li₃PO₄ (aq) ---> Sr₃(PO₄)₂ (s) + 6 LiCl (aq)</em>
Answer:-
,
, ![[CO_3^2^-]=0.254M](https://tex.z-dn.net/?f=%5BCO_3%5E2%5E-%5D%3D0.254M)
Solution:- We are asked to calculate the molarity of sodium carbonate solution as well as the sodium and carbonate ions.
Molarity is moles of solute per liter of solution. We have been given with 6.73 grams of sodium carbonate and the volume of solution is 250.mL. Grams are converted to moles and mL are converted to L and finally the moles are divided by liters to get the molarity of sodium carbonate.
Molar mass of sodium carbonate is 105.99 gram per mol. The calculations for the molarity of sodium carbonate are shown below:

= 
So, molarity of sodium carbonate solution is 0.254 M.
sodium carbonate dissociate to give the ions as:

There is 1:2 mol ratio between sodium carbonate and sodium ion. So, the molarity of sodium ion will be two times of sodium carbonate molarity.
= 0.508 M
There is 1:1 mol ratio between sodium carbonate and carbonate ion. So, the molarity of carbonate ion will be equal to the molarity of sodium carbonate.
![[CO_3^2^-]=0.254M](https://tex.z-dn.net/?f=%5BCO_3%5E2%5E-%5D%3D0.254M)