First find the number of moles of the sodium bicarbonate by dividing the mass you have(12.5g) by the molar mass of the compound(84.0g) to get .149 moles.
Then divide the number of moles (.149mol) by the number of liters of solute (.350L) to get the molarity which is .426 M or .426 mol/L to the correct number of significant figures
Molarity = Grams/(Molecular Weight X Volume)
Given:
grams = 12.5g ; molecular weight of NAHCO3 = 84.00661 g/mol ; volume =350ml or 0.35L
Solution
Molarity = 12.5 g / ( 84.00661 g/mol x 0.35 L)
= 12.5 g / ( 29.4023135 g/mol L )
= 0.425136614 mol L or approx 0.43 mol L
79.0 g NaC2H3O2 I think
The needed mass is 35,549 g.
The answer is 6,71 g dried KCl.
30 grams
NaC2H3O2 14.5 g NaC2H3O2 (1 mole NaC2H3O2/82.034 grams)(6.022 X 10^23/1 mole NaC2H3O2) = 1.06 X 10^23 atoms of sodium acetate
160 g (solution) - [5/100*160] g (solute) = 152 g (solvent) water
1.17 grams :)
The needed mass is 35,549 g.
See the two Related Questions to the left for the answer.The first is how to prepare a solution starting with a solid substance (and dissolving it). The second question is how to prepare a solution by diluting another solution.
The answer is 6,71 g dried KCl.
600 mL of 0,9 % sodium chloride: 6 x 0,9 = 5,4 grams NaCl
Molarity = moles of solute/Liters of solution 0.75 M KCl = moles KCl/2.25 Liters = 1.6875 moles KCl (74.55 grams/1 mole KCl) = 126 grams of KCl needed
30 grams
NaC2H3O2 14.5 g NaC2H3O2 (1 mole NaC2H3O2/82.034 grams)(6.022 X 10^23/1 mole NaC2H3O2) = 1.06 X 10^23 atoms of sodium acetate
160 g (solution) - [5/100*160] g (solute) = 152 g (solvent) water
4314.9 grams
28 gram. = 2 * 56 * 250 / 1000
8.9g