When u add the solution to the chemical's
A Chemical change is any form of chemical reaction changing the state of the matter involved. When you fry an egg, you are making a reaction between the heat and the chemicals that make up the egg. Therefore once you have fried that egg, you have completed a chemical reaction. This is why it's a chemical change when you fry an egg.
Don't understand the text, but water always freezes at 0°C as long as its water.

Electric current can be generated by moving a metal wire through a magnetic field. It is also different than static electricity, which is the accumulation of charges on a surface. <u>Electric generators rotate a coil</u> of wires through a magnetic field.
The amount ( in moles of excess reactant that is left is 0.206 moles
Explanation
FeS(s) + 2HCl (aq) → FeCl2 (s) + H2S (g)
- by use of mole ratio of FeS: HCl which is 1:2 this means that 0.223 mole of FeS reacted completely with 0.223 x 2/1 =0.446 moles 0f FeCl2.
- HCl was in excess because 0.446 moles of HCl reacted and initially there was 0.652 moles.
- Therefore the amount that was left
= 0.652- 0.446 =0.206 moles