I believe You replace the ending of the elements name with -ide. example: magnesium flourine should should be magnesium flouride.
Always use least amount of sig figs possible. So this 9.7 would be (answer): 2 sig figs
H2SO4 or hydrogen sulfate is an acid and NaOH or sodium hydroxide is a base or an alkali. The reaction between an acid and a base or alkali produces a salt and water. The reaction between these substances is shown below:
H2SO4 (aq) + 2NaOH (aq)------>2H20 (L) + Na2SO4 (aq). The salt produced in this reaction is sodium sulfate.
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
I think it’s B but not 100% sure
