Which property of borosilicate glass makes it suitable for thermal shock resistance ?

Question

Examoogle · Accepted Answer

The correct answer is Option A: Low thermal expansion coefficient.. Borosilicate glass is highly resistant to thermal shock because it has a very low coefficient of linear thermal expansion. This property minimizes the internal stress induced by rapid temperature changes, preventing the glass from cracking or shattering under thermal gradients.

Step-by-Step Solution & Concepts:
Borosilicate glass is highly resistant to thermal shock because it has a very low coefficient of linear thermal expansion. This property minimizes the internal stress induced by rapid temperature changes, preventing the glass from cracking or shattering under thermal gradients.

Working Principle: When a material is subjected to a temperature gradient, differential expansion or contraction occurs. The thermal stress generated is proportional to the coefficient of thermal expansion ($\alpha$). By incorporating boron trioxide ($B_2O_3$) into the silicate network, the structure becomes more stable, leading to a significantly lower $\alpha$ compared to ordinary soda-lime glass. Consequently, the induced stress $\sigma$ remains below the fracture strength of the material during rapid heating or cooling cycles.

Key Formulas: $\sigma = \frac{E \cdot \alpha \cdot \Delta T}{1 - 
u}$ — thermal stress formula where $E$ is Young's modulus, $\alpha$ is the coefficient of thermal expansion, $\Delta T$ is the temperature change, and $
u$ is Poisson's ratio.; $\alpha = \frac{1}{L} \cdot \frac{dL}{dT}$ — coefficient of linear thermal expansion.

Key Points: Borosilicate glass typically contains 70-80\% silica and 7-13\% boron trioxide.; It is commonly marketed under trade names like Pyrex or Duran.; Low thermal expansion prevents structural fatigue in laboratory and industrial equipment.

Advantages: High chemical durability; High resistance to thermal shock; Low electrical conductivity

Disadvantages: Higher production cost compared to soda-lime glass; Requires higher melting temperatures during manufacturing

Applications: Laboratory glassware (beakers, flasks); Industrial sight glasses; Pharmaceutical primary packaging

Additional Info: The coefficient of thermal expansion for borosilicate glass is approximately $3.3 	imes 10^{-6} / ^\circ C$, whereas soda-lime glass is roughly $9 	imes 10^{-6} / ^\circ C$.. Option B (Low density) is an inherent property but does not determine thermal shock resistance. Options C and D relate to optical properties, not mechanical stability.

Answer: A is correct — Borosilicate glass possesses a low thermal expansion coefficient, which limits the physical distortion and stress caused by rapid temperature fluctuations.

Exam Tip: Always remember that thermal shock resistance is inversely related to the coefficient of thermal expansion ($\alpha$); look for materials with low $\alpha$ for applications involving high heat fluxes.

Examoogle · Answer

Option B: Low density

Examoogle · Answer

Option C: High refractive index

Examoogle · Answer

Option D: High transparency

Correct Answer

Solve 10,000+ More Questions with AI Tutor

Discussion (0)

Correct Answer

Solve 10,000+ More Questions with AI Tutor

Related Questions

Discussion (0)