GCSE OCR Gateway Chemistry: Combined Science 2.1 Ionic, Covalent & Metallic Bond: Hydrogen can form compounds with

Question

Hydrogen can form compounds with the Group 7 elements. These compounds are simple covalent molecules.

For example,

hydrogen + chlorine → hydrogen chloride

H₂ + Cl₂ → 2HCl!

When simple covalent molecules are heated, they thermally decompose back into their elements.

For example,

hydrogen chloride ⇒ hydrogen + chlorine

2HCl → H₂ + Cl₂

Tables 13.1 and 13.2 show information about the compounds formed from hydrogen and some Group 7 elements.

Table 13.1

| Compound           | Structure of molecule | Boiling point (°C) | Temperature needed for thermal decomposition (°C) |
|--------------------|-----------------------|---------------------|---------------------------------------------------|
| hydrogen chloride   | H-Cl                  | -85                 | over 1500                                           |
| hydrogen bromide    | H-Br                  | -67                 | over 1000                                           |
| hydrogen iodide     | H-I                   | -35                 | over 200                                           |

Table 13.2

| Compound           | Structure of molecule | Size of molecule (pm) | Strength of covalent bond (kJ/mol) |
|--------------------|-----------------------|------------------------|--------------------------------------|
| hydrogen chloride   | H-Cl                  | 127                    | 431                                  |
| hydrogen bromide    | H-Br                  | 141                    | 366                                  |
| hydrogen iodide     | H-I                   | 161                    | 299                                  |

Hydrogen can form compounds with the Group 7 elements - OCR Gateway - GCSE Chemistry: Combined Science - Question 13 - 2022 - Paper 1

Worked Solution & Example Answer:Hydrogen can form compounds with the Group 7 elements - OCR Gateway - GCSE Chemistry: Combined Science - Question 13 - 2022 - Paper 1

Join the GCSE students using SimpleStudy...

Other GCSE Chemistry: Combined Science topics to explore