The estimated concentration of gold in the oceans is 1.0 * 10^-11 g/mL. (a) Express the concentration in mol/L.

Verified step by step guidance

1. Identify the given concentration of gold in the ocean as 1.0 \times 10^{-11} \text{ g/mL}.
2. Convert the concentration from g/mL to g/L by multiplying by 1000, since there are 1000 mL in a L.
3. Determine the molar mass of gold (Au) from the periodic table, which is approximately 197 \text{ g/mol}.
4. Use the formula for molarity: \text{Molarity (mol/L)} = \frac{\text{mass (g/L)}}{\text{molar mass (g/mol)}}.
5. Substitute the values into the formula to express the concentration in mol/L.

Key Concepts

Molarity

Molarity is a measure of concentration defined as the number of moles of solute per liter of solution. It is commonly expressed in units of mol/L. To convert grams of a substance to moles, one must use the molar mass of the substance, which is the mass of one mole of that substance in grams.

Molar Mass of Gold

The molar mass of gold (Au) is approximately 197 g/mol. This value is essential for converting the mass of gold in grams to moles, which is necessary for expressing concentration in mol/L. Knowing the molar mass allows for accurate calculations when dealing with solutions and concentrations in chemistry.

Unit Conversion

Unit conversion is the process of converting a quantity expressed in one set of units to another set of units. In this context, it involves converting the concentration of gold from grams per milliliter (g/mL) to moles per liter (mol/L). This requires understanding the relationship between grams, moles, and liters, as well as applying appropriate conversion factors.