Cr
Step 1: Understanding Beryllium Alloys
Beryllium forms several alloys, but one of the most notable is beryllium copper (\( Be-Cu \)). This alloy is widely used due to its high strength, good electrical conductivity, and non-magnetic properties.
Step 2: Properties and Applications of Beryllium Copper
- Beryllium copper (\( Be-Cu \)) is a non-sparking, non-magnetic alloy with excellent strength and corrosion resistance. - It is used in the manufacture of high-strength springs, precision instruments, and aerospace components. - The combination of beryllium with copper enhances mechanical strength while maintaining electrical conductivity.
Step 3: Evaluating the Given Options
- Option (1) Al: Beryllium-aluminum alloys exist but are not commonly used for high-strength springs.
- Option (2) Zn: Zinc alloys do not typically involve beryllium in significant amounts for mechanical applications.
- Option (3) Cu: Correct, as beryllium copper is used in high-strength springs.
- Option (4) Cr: Chromium forms strong alloys but is not the primary metal used with beryllium for this application.
Thus, the correct answer is
Option (3).
| Molisch's lest | Barfoed Test | Biuret Test | |
|---|---|---|---|
| A | Positive | Negative | Negativde |
| B | Positive | Positive | Negative |
| C | Negative | Negative | Positive |
The \( \Delta_f H^\theta \) of \( AO_3(s) \), \( BO_2(s) \), and \( ABO_3(s) \) is -635, \( x \), and -1210 kJ mol\(^{-1}\) respectively. The reaction:
\( ABO_3 (s) \rightarrow AO_3 (s) + BO_2 (g) \)
Has an enthalpy change of \( \Delta_r H^\theta = 175 \) kJ mol\(^{-1}\). What is the value of \( x \) (in kJ mol\(^{-1}\))?
At 27°C, 100 mL of 0.5 M HCl is mixed with 100 mL of 0.4 M NaOH solution. To this resultant solution, 800 mL of distilled water is added. What is the pH of the final solution?
The bromides formed by the cleavage of ethers A and B with HBr respectively are:

Match the following carboxylic acids with their pKa values.
