Best Answer
1 mole of a substance contains 6.022x10^23 "units" of that substance.
So 0.187 mol of Na+ is 1.13x10^23 ions (6.022x10^23 x 0.187).
Answer:
3.11%
Explanation:
We express a solution's volume by volume percent concentration, % v/v,
Take the ratio of the isopropyl alcohol (IPA) volume to the total volume of the solution, which is 1400 mL of water+ 45 mL of IPA,
and multiply by 100 to get the percentage: 45/(1400+45) *100 = 0.0311*100 = 3.11%
Answer:
You would get 19.969 moles
Explanation:
Answer:The heat that fuels the hot spot comes from very deep in the planet. This heat causes the mantle in that region to melt. The molten magma rises up and breaks through the crust to form a volcano. While the hot spot stays in one place, rooted to its deep source of heat, the tectonic plate is slowly moving above it.
Explanation:
The balanced equation for the reaction is as follows;
Ca(OH)₂ + 2HBr --> CaBr₂ + 2H₂O
stoichiometry of Ca(OH)₂ to HBr is 1:2
number of Ca(OH)₂ moles reacted - 0.10 mol/L x 0.1000 L = 0.010 mol
Number of HBr moles added - 0.10 mol/L x 0.4000 = 0.040 mol
1 mol of Ca(OH)₂ needs 2 mol of HBr for neutralisation
therefore 0.010 mol of Ca(OH)₂ needs - 0.010 x 2 = 0.020 mol of HBr to be neutralised
but 0.040 mol of HBr has been added therefore number of moles of HBr in excess - 0.040 - 0.020 = 0.020 mol
then pH of the medium can be calculated using the excess H⁺ ions
HBr is a strong acid therefore complete ionization
[HBr] = [H⁺]
[H⁺] = 0.020 mol / (100.0 + 400.0 mL)
= 0.020 mol / 0.5 L
= 0.040 mol/L
pH = -log[H⁺]
pH = - log [0.040 M]
pH = 1.40
pH of the medium is 1.40
