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
I believe the answer to your question would be Fluorine. I hope I answered your question, my friend. :)
The answer is C, a catalyst. This is due to the fact that catalysts are substances that can be used to speed up a reaction by lowering the activation energy required. However, the catalyst itself is not actually used up during the reaction.
Given the mass percentage of HCl solution = 15.00 %
This means that 15.00 g HCl is present in 100 g solution
Moles of HCl = 
Density of the solution = 1.075 g/mL
Calculating the volume of solution from density and mass:

Converting volume from mL to L:

Calculating the molarity of HCl solution from moles and volume:
