Pharmaceutical Chemistry

Solubility Calculator

Calculates solubility from normality and gram equivalent weight with S = N × G.W / 10.

Solubility

5.85g/L

Good solubility - soluble

Pharmacy guidelines

Moderate solubility. May require stirring or gentle heating for complete dissolution.

Inputs

Normality, N (eq/L)

eq/L

Number of gram equivalent weights per litre.

Gram equivalent weight, G.W (g/eq)

g/eq

Molecular weight divided by the n-factor. NaCl is 58.5 g/eq.

Output unit

Significant figures

Ordinary values are rounded to this many decimal places; very large or small ones switch to scientific notation.

Try an example

Working

Your values substituted into S = N × G.W / 10.

Normality (N)1eq/L

Gram equivalent weight58.5g/eq

Substitution(1) × (58.5) / 10 = 5.85g/L

Common substances

Approximate aqueous solubility at room temperature.

Substance	Formula	Solubility (g/L)
Sodium Chloride	NaCl	360
Sucrose	C₁₂H₂₂O₁₁	2000
Calcium Carbonate	CaCO₃	0.013
Silver Chloride	AgCl	0.0019
Glucose	C₆H₁₂O₆	910

S = N × G.W / 10

S — solubility in g/L. N — normality in eq/L. G.W — gram equivalent weight in g/eq.

Note: this formula converts the result from g/100mL to g/L.

For the other output units the calculator multiplies the g/L figure by 1000 (mg/mL) or divides it by the gram equivalent weight (mol/L).

Normality CalculatorGet normality and equivalent weight from a weighed amount first.

References

Beckett AH, Stenlake JB. Practical Pharmaceutical Chemistry, Part 1. 4th ed. London: Athlone Press; 1988.

Common questions

The molecular weight divided by the n-factor — the number of H⁺ or OH⁻ ions exchanged, or the total charge for a salt. HCl (n = 1) has G.W 36.46 g/eq; H₂SO₄ (n = 2) has 98.08 ÷ 2 = 49.04 g/eq.

The number of gram equivalents of solute per litre of solution. For a substance with n-factor 1 it equals molarity; for H₂SO₄ a 1 M solution is 2 N.

The solubility scale is applied to the number shown, in whichever unit is selected. The same solution gives a larger number in mg/mL and a smaller one in mol/L, so it lands in a different band.

For ordinary values it sets how many decimal places are kept (trailing zeros are dropped). For values of 10,000 or more, or below 0.001, the result switches to scientific notation with that many significant figures.

Prepared by the PharmaWallah student team. Verify results with your textbook or instructor. Report an error · Editorial policy