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1. Salts of metals can be prepared by reacting the metal with an acid to produce the salt and hydrogen - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 1
Question 1
1. Salts of metals can be prepared by reacting the metal with an acid to produce the salt and hydrogen. (i) Describe the test to show the gas is hydrogen. (ii) Nic... show full transcript
Worked Solution & Example Answer:1. Salts of metals can be prepared by reacting the metal with an acid to produce the salt and hydrogen - Edexcel - GCSE Chemistry Combined Science - Question 1 - 2018 - Paper 1
Step 1
Describe the test to show the gas is hydrogen.
Answer
To test for hydrogen gas, you should first apply a lit splint to the gas being tested. If hydrogen is present, it will produce a 'pop' sound, indicative of a combustion reaction. This 'popping' sound occurs when a small amount of hydrogen gas ignites on contact with the flame of the splint, confirming the presence of hydrogen.
Step 2
Explain how the structure of a nickel atom, Ni, changes when it forms a nickel ion, Ni²⁺.
Answer
When a nickel atom (Ni) forms a nickel ion (Ni²⁺), it undergoes the process of oxidation, which involves the loss of two electrons. In its atomic form, a nickel atom has 28 electrons. Upon losing these two electrons, the structure of the atom changes as it transforms into a positively charged ion with a total of 26 electrons. This change alters the electrical balance of the atom, resulting in the Ni²⁺ ion, which has a higher positive charge and is more stable in ionic compounds.