4 marksThis question is about silicon and carbon.
Silicon is a semiconductor.
Data obtained using the mass spectrum of silicon are shown.
| Isotope mass number | Relative abundance |
| 28 | 92.17 |
| 29 | 4.71 |
| 30 | 3.12 |
Calculate the relative atomic mass of silicon to two decimal places.
(2)
(1)
| Isotope | Number of protons | Number of neutrons |
| 28Si | ||
| 29Si | ||
| 30Si |
(1)
Silicon dioxide, SiO2 , is the main constituent of sand and has a giant lattice structure similar to that of diamond.
Crystalline silicon dioxide is used on the surface of semiconductor devices to provide a heat-resistant, electrically insulating layer.
Explain how the structure and bonding of silicon dioxide make it useful for this application.
3 marksCalcium silicate is formed in the removal of silicon dioxide impurities in the extraction of iron from its ores. A sample of calcium silicate composed of calcium, silicon and oxygen was found to contain 12.0 g of calcium, 8.43 g of silicon and 14.47 g of oxygen.
Determine the empirical formula of calcium silicate.
You must show your working.
4 marksCarbon dioxide is a gas at room temperature. A fizzy drink is canned at 5.0°C and 1.3 × 105 Pa and contains approximately 3 g of carbon dioxide.
Calculate the volume, in cm3, occupied by 3.00 g of carbon dioxide gas at 5.0°C and 1.3 × 105 Pa.
[pV = nRT R = 8.31 Jmol−1K−1]
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