Final answer:
The question seeks the concentration of Eu(III) in a groundwater sample, given that a standard contains 0.155 ng/mL (ppb). Without additional information, the concentration in the sample cannot be determined. The concept involves environmental chemistry and the use of ppb units to express contaminant levels in water.
Step-by-step explanation:
The question is asking to calculate the concentration of Eu(III) in a groundwater sample, where the added standard contained 0.155 ng/mL (ppb) of Eu(III). To calculate the concentration in a sample, we typically need more information such as the volume of the groundwater sample or the results from an analytical method. Assuming we had such data, we could use it alongside the known concentration of the standard to determine the concentration in the sample.
In environmental chemistry, understanding concentrations is important for assessing water quality and pollution levels.
For example, if we were given that an environmental sample had a Eu(III) concentration of 0.155 ppb, we can express that concentration directly as it is already in the desired units (parts per billion), which is a common unit used to represent contaminant levels in water.