a coin is composed of gold and silver. the 5.00g coin is dissolved in nitric acid and the solution treated with NaCl to precipitate out 2.35g of AgCl. Gold chlorides do not precipitate under the same conditions.
What is the composition of silver (by mass) in this coin?
Two or three things I want to point out to you. First, note the correct spelling of chemistry. Second, Au is NOT soluble in HNO3 alone. That's why Au is called a noble metal and it requires aqua regia (royal water) to dissolve it. Aqua regia is a mixture of HNO3 and HCl. For the problem:
Convert 2.35g AgCl to g Ag (find percent Ag in AgCl) and %Ag(as a fraction) x 2.35 = g Ag.
%Ag = (g Ag/g sample)*100 =
To determine the composition of silver (by mass) in this coin, we can use the information given in the question.
Given:
- Total mass of the coin = 5.00g
- Mass of AgCl precipitate = 2.35g
First, we need to calculate the amount of silver in AgCl. The molar mass of AgCl is 143.32 g/mol, with one mole of AgCl containing one mole of silver (Ag).
Using the molar mass of AgCl, we can calculate the moles of AgCl:
moles of AgCl = mass of AgCl / molar mass of AgCl = 2.35g / 143.32 g/mol
Next, we know that one mole of AgCl contains one mole of silver (Ag). So, the number of moles of Ag is equal to the number of moles of AgCl:
moles of Ag = moles of AgCl
Since the molar mass of Ag is 107.87 g/mol, we can calculate the mass of silver:
mass of Ag = moles of Ag * molar mass of Ag
Finally, to find the composition of silver in the coin, we need to express the mass of silver as a percentage of the total mass of the coin:
composition of silver (%) = (mass of Ag / total mass of the coin) * 100
By following these steps and substituting the values, you can calculate the composition of silver (by mass) in the coin.
To determine the composition of silver (by mass) in this coin, we need to use the given information and perform some calculations. Here's how you can do it:
1. Start by calculating the amount of silver (Ag) in the form of AgCl that was precipitated. We know that the 2.35g of AgCl was obtained from the coin.
2. The molar mass of AgCl is 143.32 g/mol. This means that 1 mole of AgCl contains 107.87 g of Ag.
3. We can use the molar ratio between AgCl and Ag to find the amount of Ag present in the 2.35g of AgCl. The molar ratio is 1:1, meaning that for every 1 mole of AgCl, we have 1 mole of Ag. Therefore, the mass of Ag in the 2.35g of AgCl is also 2.35g.
4. Now, we need to calculate the total mass of the coin, assuming that all the mass of Ag is in the form of AgCl. The total mass of the coin is 5.00g.
5. Finally, calculate the composition of silver by dividing the mass of Ag (2.35g) by the total mass of the coin (5.00g) and multiplying it by 100 to express it as a percentage:
Composition of silver = (mass of Ag / total mass of the coin) * 100
Composition of silver = (2.35g / 5.00g) * 100
By performing this calculation, we find that the composition of silver (by mass) in this coin is approximately 47%.