ESTABLISHED 2012 · AHMEDABAD, INDIA☎ +91 97379 73334✉ info@hmpharmamachines.com
Solution Chemistry

Serial Dilution: Multiply the Transfer Fractions Across Stages

Several dilution steps form one transfer history. A final concentration should follow the fraction retained at every aliquot stage, using final solution volumes.

Library dates organize the collection. Actual publication and revision dates are shown separately.

Several dilution steps form one transfer history. A final concentration should follow the fraction retained at every aliquot stage, using final solution volumes.

Retain each aliquot and final volume

For a nonreacting homogeneous solute, an aliquot carries the stock’s amount concentration multiplied by aliquot volume. Dilution to a known final volume changes concentration while conserving that transferred amount. Applying several stages requires the transfer fraction from each stage. Primary reference.

Trace a fictional two-stage preparation

Start an invented preparation at 2.00 mol/L. Transfer 5.00 mL and make that solution up to a final 50.0 mL: its concentration is 2.00 × 5.00/50.0 = 0.200 mol/L. Then transfer 2.00 mL of that solution and make up to final 100 mL, giving 0.00400 mol/L.

The combined retained concentration fraction is (5/50) × (2/100) = 0.002. The inverse overall dilution factor is 500 under this convention. Describing the second stage as a fifty-fold dilution should not erase the first stage’s ten-fold change.

Keep the original stock connected to the result

Prepare an original stage register with stock identity, aliquot source, transfer volume and final volume. Keep make-up-to-final-volume distinct from adding that many millilitres of diluent. A skipped stage or a wrong source bottle can produce a plausible final number with the wrong preparation history.

The arithmetic assumes the selected solute remains dissolved, homogeneous and unreacted. It is not a recommended sampling procedure, laboratory uncertainty evaluation or machine recipe. The review decision is whether the final concentration can be reconstructed from the complete stated sequence.

Solution review worksheet

This blank worksheet is for your own project. It contains no H M machine trial result.

Solution review worksheet
QuestionRecord to retain
Which solution fed each stage?Stock or preceding stage identity
Which fraction was transferred?Aliquot volume divided by final solution volume
Which factor convention is reported?Retained fraction or its inverse

Customer Questions

What is the fictional final concentration?

0.00400 mol/L.

What is the overall inverse dilution factor?

500 under the defined convention.

Is final volume the same as added diluent volume?

Not by definition. The preparation record must distinguish them.

Primary References

These references support the technical principles discussed in this guide. The worked examples and review questions are educational.

Discuss Your Machine Requirement

Share your product, container, required output and the evidence needed for your technical review.

Request a Technical Review