Silver chloride, often used in silver plating, contains 75.27% Ag by mass. Calculate the mass of silver chloride required to plate 155 mg of pure silver.

Verified step by step guidance

1. Step 1: Understand the problem. We know that silver chloride contains 75.27% silver by mass. This means that for every 100 grams of silver chloride, there are 75.27 grams of silver. We need to find out how much silver chloride is needed to get 155 mg of silver.
2. Step 2: Convert the percentage of silver in silver chloride to a decimal by dividing by 100. So, 75.27% becomes 0.7527.
3. Step 3: Use the formula for finding the mass of a whole when the mass of a part and the percent composition are known. The formula is: mass of whole = (mass of part) / (percent composition). In this case, the 'mass of part' is the mass of silver we want (155 mg) and the 'percent composition' is the decimal equivalent of the percentage of silver in silver chloride (0.7527).
4. Step 4: Substitute the known values into the formula. So, mass of silver chloride = (155 mg) / (0.7527).
5. Step 5: Solve the equation to find the mass of silver chloride needed. This will give you the amount of silver chloride required to plate 155 mg of pure silver.

Key Concepts

Mass Percent Composition

Mass percent composition is a way to express the concentration of an element in a compound, calculated as the mass of the element divided by the total mass of the compound, multiplied by 100. In this case, knowing that silver chloride (AgCl) contains 75.27% silver by mass allows us to determine how much AgCl is needed to obtain a specific mass of silver.

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows us to convert between grams of one substance and grams of another using their molar masses, which is essential for calculating how much silver chloride is needed to provide a certain mass of silver.

Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). For silver chloride, the molar mass can be calculated by adding the atomic masses of silver (Ag) and chlorine (Cl). This value is crucial for converting between mass and moles, which is necessary for stoichiometric calculations in this problem.