Kütlece

Kütlece is a Turkish term used in scientific and technical contexts to indicate a proportion that is based on mass. It denotes a ratio or fraction expressed with respect to the total mass of a mixture, rather than its volume or the number of molecules.

In chemistry and related fields, kütlece is widely used to describe concentrations and compositions. Common phrases include kütlece yüzde and kütlece oranı, which translate to mass percentage or mass fraction. For example, a solution with 30 grams of solute per 100 grams of solution has a kütlece yüzde (mass percentage) of 30% and a mass fraction of 0.30. The term is often contrasted with hacimce (by volume), which expresses ratios based on volume.

Synonyms and related expressions in Turkish include ağaırlıkça and yüze göre phrases that convey the same general idea of mass-based proportion. In practice, kütlece is used across disciplines such as chemistry, chemical engineering, pharmacology, geology, and environmental science to specify composition or concentration in terms of mass.

Terminology notes: strictly, kütle refers to mass and ağırlık refers to weight (the gravitational force on a mass). In everyday language these terms can overlap, and many Turkish texts use kütlece and ağırlıkça interchangeably to denote mass-based fractions. However, when precision matters, it is important to distinguish mass-based (kütle) from weight-based (ağırlık) references.