What does dH2O refer to?

dH2O refers to deionized water, which is water that has had its mineral ions removed, such as sodium, calcium, iron, and copper. This process typically involves ion exchange or distillation, rendering the water free of dissolved minerals. This makes dH2O very pure and suitable for laboratory use, where the presence of other ions could interfere with experiments or tests.

In common practices, using deionized water is crucial in analytical chemistry, biochemistry, and various other scientific disciplines where the purity of water directly affects the results of experiments and the performance of chemical reactions.