Answer:
pH = 5.7
Explanation:
pH = -log[H^+]
For HCl pH = -log[HCl] = - log [2.10 x 10⁻⁶ ] = 5.7
Answer:
Fe(NO3)3 + 3 NaOH ===》Fe(OH)3 + 3 NaNO3
A. A pure chemical substance consisting of one type of atom
The correct answer is B.
1 mol O2 x 15.999 O2/ 1 mol O2 = 15.999 O2
16 O2 when rounded.
In an oxidation-reduction reaction there is an exchange of electrons.
The exchange of electrons implies change in the oxidation states: at least one element increases its oxidation number while other reduces it.
By simple ispection you can predict that in the equation b. there is a change in oxidation states of Cl and Mn.
Now you can check it:
Equation 4H Cl + Mn O2 -> Mn Cl2 + 2H2 O + Cl2
oxidation sates 1+ 1- 4+ 2- 2+ 1- 1+ 2- 0
The oxidation state of Cl in HCl is 1- and it changed to 0 in Cl2
The oxidation state of Mn in MnO2 is 4+ and it changed to 2+ in MnCl2
Answer b.