Chapter 11, Problem 11.47P

Interpretation Introduction

(a)

Interpretation:

State that the copper element A or element B is labeled in given phase diagram of copper-silver metals.

  

Fig. $1$ - Phase diagram of copper-silver metals

Concept Introduction:

The properties of the copper-silver alloy are as follows-

1. Melting point − $\left(\text{779-900}\right)\text{°C}$

2. Molecular weight − $\text{171}\text{.41}$

3. Density − $\left(\text{9}\text{.7-10}\text{.4}\right)\text{g/cm³}$

4. Insoluble in water

In the case of silver and copper alloy, both of these are not able to melt together and form a new alloy with $\left(\text{1-99}\right)\text{\%}$ of any one in pure form. That's why the alloy of this case, are mostly available in the following forms −

1. Sterling silver − In sterling silver, the weight percentage of pure silver is $92\%$

2. Coin silver - The weight percentage of pure silver available in coin silver is $90\%$

There is a new alloy also available known as Electrum. In this alloy, the weight percentage of silver is from $\left(\text{20 - 80}\right)\text{\%}$.

Interpretation Introduction

(b)

Interpretation:

The well labelled phase diagram of the copper silver alloy needs to be sketched.

Concept Introduction:

The properties of the copper-silver alloy are as follows-

1. Melting point − $\left(\text{779-900}\right)\text{°C}$

2. Molecular weight − $\text{171}\text{.41}$

3. Density − $\left(\text{9}\text{.7-10}\text{.4}\right)\text{g/cm³}$

4. Insoluble in water

In the case of silver and copper alloy, both of these are not able to melt together and form a new alloy with $\left(\text{1-99}\right)\text{\%}$ of any one in pure form. That's why the alloy of this case, are mostly available in the following forms −

1. Sterling silver − In sterling silver, the weight percentage of pure silver is $92\%$

2. Coin silver - The weight percentage of pure silver available in coin silver is $90\%$

There is a new alloy also available known as Electrum. In this alloy, the weight percentage of silver is from $\left(\text{20 - 80}\right)\text{\%}$.

Interpretation Introduction

(c)

Interpretation:

Whether the new composition is stronger or weaker needs to be determined, if it cools down at $\text{600}$ °C with $90$ % A and $10$ % B.

Concept Introduction:

The properties of the copper-silver alloy are as follows-

1. Melting point − $\left(\text{779-900}\right)\text{°C}$

2. Molecular weight − $\text{171}\text{.41}$

3. Density − $\left(\text{9}\text{.7-10}\text{.4}\right)\text{g/cm³}$

4. Insoluble in water

In the case of silver and copper alloy, both of these are not able to melt together and form a new alloy with

  $\left(\text{1-99}\right)\text{\%}$ of any one in pure form. That's why the alloy of this case, are mostly available in the following forms −

1. Sterling silver − In sterling silver, the weight percentage of pure silver is $92\%$

2. Coin silver - The weight percentage of pure silver available in coin silver is $90\%$

There is a new alloy also available known as Electrum. In this alloy, the weight percentage of silver is from $\left(\text{20 - 80}\right)\text{\%}$.

Interpretation Introduction

(d)

Interpretation:

The statement "microstructure can lead to the discrepancy" needs to be justified by giving an example.

Concept Introduction:

The properties of the copper-silver alloy are as follows-

1. Melting point − $\left(\text{779-900}\right)\text{°C}$

2. Molecular weight − $\text{171}\text{.41}$

3. Density − $\left(\text{9}\text{.7-10}\text{.4}\right)\text{g/cm³}$

4. Insoluble in water

In the case of silver and copper alloy, both of these are not able to melt together and form a new alloy with $\left(\text{1-99}\right)\text{\%}$ of any one in pure form. That's why the alloy of this case, are mostly available in the following forms −

1. Sterling silver − In sterling silver, the weight percentage of pure silver is $92\%$

2. Coin silver - The weight percentage of pure silver available in coin silver is $90\%$

There is a new alloy also available known as Electrum. In this alloy, the weight percentage of silver is from $\left(\text{20 - 80}\right)\text{\%}$.