Silica is used to make all types of glass.
(a) State the type of glass that is made up of only silica.
(b) Soda-lime glass contains alkali metal ions. Name the ion.
Answer:
(a) Fused silica glass
(b) Sodium ion
A sample of borosilicate glass has composition of 80% silica, SiO2, 15% boron oxide, B2O3 and 5% alumina, Al2O3. Calculate the mass of each component in the borosilicate glass sample with mass of 1 kg.
Answer:
$$
\text { Mass of silica, } \begin{aligned}
\mathrm{SiO}_2 & =\frac{80}{100} \times 1000 \mathrm{~g} \\
& =800 \mathrm{~g}
\end{aligned}
$$
$$
\text { Mass of boron oxide, } \begin{aligned}
\mathrm{B}_2 \mathrm{O}_3 & =\frac{15}{100} \times 1000 \mathrm{~g} \\
& =150 \mathrm{~g}
\end{aligned}
$$
$$
\text { Mass of alumina, } \begin{aligned}
\mathrm{Al}_2 \mathrm{O}_3 & =\frac{5}{100} \times 1000 \mathrm{~g} \\
& =50 \mathrm{~g}
\end{aligned}
$$
Aini’s mother : Aini, do not store food in lead crystal glass containers.
Aini: Why not, mother?
Based on the conversation above, explain the advantages and disadvantages of using containers made from lead crystal glass.
Answer:
Advantages:
• The transparent property enables the food in the container to be visible
• Can be easily cleaned and does not leave any traces
• High heat resistance
Disadvantages:
• Heavy because lead glass has high density
• Risk of lead poisoning, as lead can dissolve and diffuse into food