Which type of glassware is labeled as "TC" (i.e., "to contain")?

The volumetric flask is appropriately labeled as "TC," which stands for "to contain." This designation indicates that the flask is designed to hold a precise volume of liquid up to a specified mark on the neck of the flask. The construction of a volumetric flask ensures that it can accurately contain a specific volume, which is critical for laboratories where precision in measurements is essential, such as in titrations or preparing solutions.

In contrast, beakers, graduated cylinders, and pipettes have different designations and uses. Beakers are typically labeled as "TD" (to deliver) because they are designed for general usage where precision is less critical. Graduated cylinders are also labeled as "TD," as they are used to measure volumes of liquids but are not made to precisely contain the volume indicated. Pipettes, while they can also have varying designs for either containing or delivering liquids, frequently bear a "TD" specification as they are intended to deliver a specified volume of liquid.

Thus, the unique "TC" labeling for the volumetric flask affirms its specialized purpose in laboratory settings for containing exact measurements.