E.g. in H3PO4 (O, -2).
8. The sum of the oxidation states of all the atoms in a species must be equal to net charge on the species. e.g. Net Charge of HClO4 = 0, i.e. [+1(H)+7(Cl)-2<span>*4(O)] = 0.</span>
Answer:
1-A
2-B
Explanation:
2- mantle is liquid and moves crust
When we go to periodic table, Sulfur is
an element that has 16 protons and 16 electrons.
when there is 18 electrons, with number of two electrons more than protons. This makes it an ion and
the ion has a -2 charge.
So when there is16 protons, 18 neutrons, and 18 electrons the symbol is S⁻².
The neutrons have no charge but they add only mass to the
elements. So when there is 16 neutrons, it doesn't change the symbol of ion.
We convert the masses of our reactants to moles and use the stoichiometric coefficients to determine which one of our reactants will be limiting.
Dividing the mass of each reactant by its molar mass:
(10 g C2H6)(30.069 g/mol) = 0.3326 mol C2H6
(10 g O2)(31.999 g/mol) = 0.3125 mol O2.
Every 2 moles of C2H6 react with 7 moles of O2. So the number of moles of O2 needed to react completely with 0.3326 mol C2H6 would be (0.3326)(7/2) = 1.164 mol O2. That is far more than the number of moles of O2 that we are given: 0.3125 moles. Thus, O2 is our limiting reactant.
Since O2 is the limiting reactant, its quantity will determine how much of each product is formed. We are asked to find the number of grams (the mass) of H2O produced. The molar ratio between H2O and O2 per the balanced equation is 6:7. That is, for every 6 moles of H2O that is produced, 7 moles of O2 is used up (intuitively, then, the number of moles of H2O produced should be less than the number of moles of O2 consumed).
So, the number of moles of H2O produced would be (0.3125 mol O2)(6 mol H2O/7 mol O2) = 0.2679 mol H2O. We multiply by the molar mass of H2O to convert moles to mass: (0.2679 mol H2O)(18.0153 g/mol) = 4.826 g H2O.
Given 10 grams of C2H6 and 10 grams of O2, 4.826 g of H2O are produced.
Answer:
12
Explanation:
You will need a chemical equation with masses and molar masses, so let’s gather all the information in one place.
: 258.21 18.02
KAl(SO₄)₂·xH₂O ⟶ KAl(SO₄)₂ + xH₂O
Mass/g: 4.74 2.16
Step 1. Calculate the mass of the KAl(SO₄)₂.
Mass = 4.74 g – 2.16 g = 2.58 g.
Step 2. Calculate the moles of each product.
Step 3. Calculate the molar ratio of the two products.
1 mol of KAl(SO₄)₂ combines with 12 mol H₂O, so x = 12.
