The balanced equation for the above neutralisation reaction is as follows;
Ca(OH)₂ + 2HCl ----> CaCl₂ + 2H₂O
Stoichiometry of Ca(OH)₂ to HCl is 1:2
number of Ca(OH)₂ moles reacted - 0.250 mol/L x 20.0 x 10⁻³ L = 5.00 x 10⁻³ mol
according to molar ratio of 1:2
number of HCl moles required = 2 x number of Ca(OH)₂ moles reacted
number of HCl moles = 5.00 x 10⁻³ x 2 = 10.0 x 10⁻³ mol
molarity of HCl solution - 0.250 M
there are 0.250 mol in volume of 1 L
therefore 10.0 x 10⁻³ mol in - 10.0 x 10⁻³ mol / 0.250 mol/L = 40.0 mL
40.0 mL of 0.250 M HCl is required
I just took a test with this question and got the answer wrong for saying ethane. The correct answer is propane.
There is 1 H atom: (1)(+1) = +1 The oxidation number of O is -2. There are 4 O atoms here: (4)(-2) = -8 So the oxidation state of Cl is +7.
NOTE: The maximum positive oxidation number for chlorine is +7,<span> the same as its group number (VII).</span>
Just search it up on the internet:)