Compounds Na₂SO₄ and NaCl are mixed together are we are asked to find the concentration of Na⁺ in the mixture
Na₂SO₄ ---> 2 Na⁺ + SO₄³⁻
1 mol of Na₂SO₄ gives out 2 mol of Na⁺ ions
the number of Na₂SO₄ moles added - 0.800 M/1000 * 100 ml
= 0.08 mol
therefore number of Na⁺ ions from Na₂SO₄ = 0.08 * 2 = 0.16 mol
NaCl ----> Na⁺ + Cl⁻
1 mol of NaCl gives 1 mol of Na⁺ ions
number of NaCl moles added = 1.20 M/1000 * 200 ml
= 0.24 mol
number of Na⁺ ions from NaCl = 0.24 mol
total number of Na⁺ ions in the mixture = 0.16 mol + 0.24 mol = 0.4 mol
as stated the volumes are additive,
therefore total volume = 100 ml + 200 ml = 300 ml
the concentration of Na⁺ ions = number of moles / volume
= 0.4 mol/ 0.3 dm³
concentration of Na⁺ = 1.33 mol/dm³
Here's a hint. One of these is a liquid, one is a gas, and one is a radioactive gas. Match each of these descriptions to the right element, and tell me which one you would be most likely to be emitted from your stove.
Proton; neutron
Protons have a positive charge
Neutrons are neutral
Electrons have a negative charge :)
Answer:
1. Balanced molecular equation:
- HF(aq) + RbOH(aq) → RbF(aq) + H₂O(l)
2. Net ionic equation:
- H⁺ (aq) + OH⁻ (aq) → H₂O(l)
Explanation:
<u>1. Write the word equation</u>
This is the reaction of an acid and a base producing salt plus water.
- hydrofluoric acid + rubidium hydroxide → rubidium fluoride + water
<u>2. Balanced molecular equation</u>
- HF(aq) + RbOH(aq) → RbF(aq) + H₂O(l) ← answer
<u />
<u>3. Write the ionic compounds in aqueous solution as ions</u>
<u />
Overall ionic equation:
- H⁺ (aq) + F⁻ (aq) + Rb⁺ (aq) + OH⁻ (aq) → Rb⁺ (aq) + F⁻ (aq) + H₂O(l)
<u>4. Cancel the spectator ions</u>
The spectator ions are those that appear in both sides of the overall ionic equation. In this case they are F⁻ (aq) and Rb⁺ (aq).
Net ionic equation:
- H⁺ (aq) + OH⁻ (aq) → H₂O(l) ← answer
<span>0.504 moles
First look up the atomic weight of mercury.
atomic weight of mercury = 200.59
Then divide the mass of the mercury you have by it's atomic weight
101 / 200.59 = 0.503515
So you have 0.503515 moles of mercury. Round the result to 3 significant digits giving you 0.504 moles.</span>
