<span>Dalton noted that the chromium oxide molecules that he was studying had masses of oxygen that were not the same: he found that there were constant ratios to these mass differences, however, so there had to be some sort of "units" (atoms) making up the ratios of these particles.</span>
0.73 M is the concentration of sulfuric acid that needed 47 mL of 0.39M potassium hydroxide solution to neutralize a 25 mL sample of the sulfuric acid solution.
Explanation:
Data given:
Volume of the base = 47 ml
molarity of the base= 0.39 M
volume of the acid = 25 ml
molarity of the acid =?
For titration reaction between acid and base, the volume or molarity of any of the base or acid can be determined. The formula used:
Macid X Vacid = Vbase x Mbase
Macid = 
putting the values given in the rearranged equation above:
Macid = 
= 0.73 M
The concentration of the sulphuric acid needed is 0.73 M.
Answer is: 7,826 kg of cryolite.
Chemical reaction: Al₂O₃ + 6NaOH + 12HF → 2Na₃AlF₆ + 9H₂<span>O.
m(</span>Al₂O₃) = 12,1 kg = 12100 g.
n(Al₂O₃) = m(Al₂O₃) ÷ M(Al₂O₃).
n(Al₂O₃) = 12100 g ÷ 101,96 g/mol = 111,86 mol; limiting reactant.
m(NaOH) = 60,4 kg = 60400 g.
n(NaOH) = 60400 g ÷ 40 g/mol.
n(NaOH) = 1510 mol.
m(HF) = 60,4 kg = 60400 g.
n(HF) = 60400 g ÷ 20 g/mol = 3020 mol.
From chemical reaction: n(Al₂O₃) : n(Na₃AlF₆) = 6 : 2.
n(Na₃AlF₆) = 2 ·111,86 mol ÷ 6 = 37,28 mol.
m(Na₃AlF₆) = 37,28 mol · 209,94 g/mol.
m(Na₃AlF₆) = 7826,56 g = 7,826 kg.
Answer:
The molar mass of any substance is the mass in grams of one mole of representative particles of that substance. ... In such a conversion, we use the molar mass of a substance as a conversion factor to convert mole units into mass units (or, conversely, mass units into mole units).
Explanation: