Question

Bromine is used to prepare the pesticide methyl bromide and flame retardants for plastic electronic housings. It is recovered from seawater, underground brines, and the Dead Sea. The average concentrations of bromine in seawater \((d=1.024 \mathrm{~g} / \mathrm{mL})\) and the Dead Sea \((d=1.22 \mathrm{~g} / \mathrm{mL})\) are \(0.065 \mathrm{~g} / \mathrm{L}\) and \(0.50 \mathrm{~g} / \mathrm{L},\) respectively. What is the mass ratio of bromine in the Dead Sea to that in seawater?

Short answer

The mass ratio of bromine in the Dead Sea to that in seawater is approximately 7.69.

Step-by-step solution

Identify the Given Values

First, note the given values in the problem: - Density of seawater: \(d_{seawater} = 1.024 \, g/mL\) - Density of Dead Sea water: \(d_{DeadSea} = 1.22 \, g/mL\) - Concentration of bromine in seawater: \(C_{seawater} = 0.065 \, g/L\) - Concentration of bromine in Dead Sea: \(C_{DeadSea} = 0.50 \, g/L\)

Understand the Concept of Mass Ratio

The mass ratio of bromine in Dead Sea water to that in seawater is calculated by comparing the concentrations of bromine in each water source.

Formulate the Mass Ratio

To find the mass ratio, divide the concentration of bromine in the Dead Sea by the concentration of bromine in seawater: \[ \text{Mass Ratio} = \frac{C_{DeadSea}}{C_{seawater}} \] Substitute the given values: \[ \text{Mass Ratio} = \frac{0.50 \, g/L}{0.065 \, g/L} \]

Calculate the Mass Ratio

Perform the division to find the mass ratio: \[ \text{Mass Ratio} = \frac{0.50}{0.065} \approx 7.69 \]

Key concepts

Bromine Concentration

When discussing bromine concentration, we are talking about the amount of bromine present in a given volume of water. The concentration is typically given in grams per liter (g/L). For example, in the exercise, the concentration of bromine in seawater is given as 0.065 g/L, whereas, in the Dead Sea, it is much higher at 0.50 g/L.

Understanding bromine concentration is vital because it helps determine how much bromine can be extracted from different water sources. Bromine is needed for various industrial applications, such as making pesticides and flame retardants. Hence, knowing its concentration in different sources helps in efficient resource extraction.

To calculate something like the mass ratio of bromine, we compare these concentrations using a simple division formula. This allows us to directly see how much more bromine is in one source compared to another, aiding in decision-making for industries reliant on bromine.

Seawater

Seawater makes up the vast majority of Earth's surface water. It contains various salts and minerals, including bromine. The average density of seawater is approximately 1.024 g/mL. This density can slightly vary based on conditions like temperature and salinity.

In the context of the exercise, seawater has a bromine concentration of 0.065 g/L. Even though this is relatively low, the immense volume of seawater means that substantial amounts of bromine can still be extracted. Bromine is dissolved in seawater along with other minerals, making it one of many valuable substances harvested from the ocean.

Understanding the properties of seawater, such as bromine concentration, is essential for marine chemistry and industries extracting resources from the ocean. This simple knowledge ensures efficient and economical strategies for bromine retrieval.

Dead Sea

The Dead Sea is one of the saltiest bodies of water on Earth, with a density of about 1.22 g/mL. Due to its high salinity, the Dead Sea has far higher mineral concentrations compared to typical seawater.

In our exercise, we see that the concentration of bromine in the Dead Sea is around 0.50 g/L. This is significantly higher than in regular seawater. The higher concentration means the Dead Sea is a richer source for bromine extraction, making it highly economical for industries that use bromine.

The elevated bromine levels in the Dead Sea are a result of its unique environment, where the high evaporation rate leads to a greater concentration of dissolved minerals. This makes the Dead Sea an important natural resource for extracting bromine and other minerals, adding to its economic value.