Question

How many mLs of each would you need to make 50mL of solution

Final concentration of solutes . Stock concentrations

MgSO4 0.83 mM MgSO4 1 M

CaCl2 0.9 mM CaCl2 1 M

KHCO3 0.04 mM KHCO3 0.1 M

NaHCO3 0.9 mM NaHCO3 0.5 M

Ocean Salts 0.21 g/L Ocean Salts 21 g/L

Answer 1

For each problem, V₁ x S₁ = V₂ x S₂ formula should be applied.

where, V₁ = volume of stock, S₁ = stock concentration, V₂ = final volume, S2 = final concentration

V₂ here in all cases is = 50 mL

For MgSO₄,   V₁ x 1000 mM = 50 mL x 0.83 mM

so, V₁ = 0.0415 mL

  0.0415 mL of MgSO₄

For CaCl₂, V₁ x 1000 mM = 50 mL x 0.9 mM

so, V₁ = 0.045 mL

  0.045 mL of CaCl₂

For KHCO₃,   V₁ x 100 mM = 50 mL x 0.04 mM

so, V₁ = 0.02 mL

0.02 mL of KHCO₃

For NaHCO₃,  V₁ x 500 mM = 50 mL x 0.9 mM

so, V₁ = 0.09 mL

0.09 mL of NaHCO₃

For Ocean salt, V₁ x 21 g/L = 50 mL x 0.21 g/L

so, V₁ = 0.5 mL  

0.5 mL of Ocean salt

Please find final answers are marked in bold and underlined.