Failure to read the last significant figure from a buret is which type of error?

• A. Personal error
• B. Systematic error
• C. Gross error
• D. Random error

Answer: (A)

Reading the last significant figure from a buret is a human judgment error. It comes from the observer’s technique or interpretation when estimating the final digit of the reading, not from the instrument itself or from random fluctuations. This kind of misreading is a personal error—a mistake in how the measurement was read or recorded by the person conducting the titration. It’s not a consistent bias in the instrument (systematic), not a random fluctuation in the measurement (random), and not a large obvious mistake (gross error). To reduce it, read at eye level with the meniscus, estimate the last digit carefully, and consider repeating readings.