pH Paper, Wide Range

Quick Answer: Wide range pH paper is indicator-impregnated paper that changes colour according to the pH of a solution, read against a printed colour chart. The listing photo shows booklets of strips in a clear plastic box, each with a chart running from red at the acidic end through yellow and green to deep blue, plus loose tear-off strips.

Estimating pH in a Few Seconds

The paper carries a blend of indicators, each changing colour over a different part of the pH scale, so together they produce a graded run of colours instead of the single switch of litmus. The chart printed on each booklet in the photo is numbered from 1 to 14, which is what ‘wide range’ means here: one strip gives a rough value anywhere across the usual scale.

To use it, tear off a short strip, touch it with a drop of the test solution on a glass rod or dip just the end briefly, and compare the colour with the chart straight away. Readings are to about one pH unit. That is enough to tell a strong acid from a weak one or to show that a soap solution is alkaline, but not enough to plot a titration curve or check a buffer.

For readings to one or two decimal places a laboratory pH meter is needed, such as the wireless pH meter sensor, which also logs readings over time. Paper stays quicker for surveys of many samples, needs no calibration and can be handed to every student at once.

Specifications

Applications

• Classifying household substances such as vinegar, soap, baking soda and lemon juice as acidic, neutral or alkaline
• Checking the pH of water samples, soil extracts or rainwater in environmental projects
• Following a neutralisation roughly as acid is added to alkali
• Confirming that waste solutions are near neutral before disposal, as lab rules require

Care & Handling

• Keep the wide range pH paper booklets closed in their box and away from acid or ammonia fumes, which change the colour of unused paper.
• Handle strips by one end with dry hands; moisture and sweat on fingers can affect the colour.
• Read the colour immediately after wetting, since colours can drift as the strip dries.
• Never dip a strip into a stock reagent bottle; test a drop taken out on a glass rod instead.

Why Choose LabEquip

Schools, colleges and environmental science groups buy wide range pH paper for quick classification work where a meter would be slower. LabEquip lists it among its chemistry lab equipment; ask on the contact page about quantities for a year of classes.

Frequently Asked Questions

How accurate is wide range pH paper?

It gives an estimate to roughly one pH unit. That is enough to classify solutions as strongly acidic, weakly acidic, neutral or alkaline, but a pH meter is needed for more precise work.

How is it different from litmus paper?

Litmus only shows whether a solution is acidic or alkaline. Wide range paper contains several indicators and gives a series of colours that can be matched to an approximate pH value.

Can pH paper test coloured solutions?

Strongly coloured liquids, such as fruit juices or dye solutions, can mask the indicator colour and give misleading readings. Dilute the sample, or use a pH meter for coloured liquids.

Why should a strip not be dipped into the stock bottle?

Indicator dyes can leach from the paper and contaminate the solution. Take a drop out on a clean glass rod and touch it to the strip instead.

Does pH paper work on distilled water?

Readings on distilled water are unreliable because it has almost no buffering, and dissolved carbon dioxide makes it slightly acidic. Expect a value a little below 7.

How should the paper be stored?

Keep it in its closed box in a dry cupboard, away from light and chemical fumes. Acid or ammonia vapour in a store room can change the colour of unused strips.

Last Updated: September 2026