Brass is a substitutional alloy consisting of a solution of copper and zinc. A particular sample of red brass consisting of 80.0 % Cu and 20.0 % Zn by mass has a density of 8750 kg/m³. (b) What is the molarity of Zn in the solution?

Video transcript

Hey everyone. Our question here states that white gold is an alloy made up of gold and palladium a bar of 14 Karat gold has a density of 16.5 g over cubic cm and contains 58.3% gold and 41.7% palladium by mass. What is the Mueller concentration of gold in the solution For this question? We're going to go ahead and assume that we have 100 g of Karat gold and this is going to make it easier for us to convert our percentages into grams. Starting off with our 58.3% of gold, we're going to say that we have 58.3 g of gold using gold atomic mass of 1 96.967 g per one mole. We're going to convert this into moles of gold. When we calculate this out, we end up with a total of 0.2960 mol of gold. And since we're looking for the Mueller concentration of gold, we need to calculate the volume. To calculate our volume, we can go ahead and start off with our 100 g since we assumed that we had 100 g of 14 Karat gold. Using our density for a dimensional analysis, we have 16.5 g per one cc and we know that one cc is the same as one millimeter. Now we want to convert this into leaders and we know that 10 to the third male leaders is the same as one leader. So calculating this out and canceling out our units, we end up with a volume Of 6.0606 times 10 to the negative 3rd leaders. Now to calculate our molar concentration of our gold, we're going to take 0.2960 mole of gold and divide this by 6.606 times 10 to the negative third Leaders. When we calculate this out, we end up with a polarity of 48.8 molar of our gold and this is going to be our final answer. So I hope this made sense and let us know if you have any questions.