Which type of laboratory container has a curved body and is used to mix solutions?

The correct answer is the flask, which is designed with a curved body, often featuring a narrow neck and a wide base. This unique shape allows for easy mixing of solutions, as the curvature promotes the movement of liquids during agitation. Flasks are especially useful in experiments that require thorough mixing or reactions that involve adding components gradually, as the shape minimizes spillage and enables secure handling.

Beakers have straight sides and a spout for pouring, which makes them more suitable for holding and measuring volumes rather than mixing. Test tubes are narrow and cylindrical, excellent for holding small amounts of liquids but not ideal for mixing larger volumes. Pipettes are specifically designed for transferring precise volumes of liquid and do not serve the purpose of mixing solutions in a laboratory setting. The distinctive design of flasks facilitates effective mixing in laboratory procedures, making it the most appropriate choice in this context.