A woman desires to clean the surface of her gold ornaments by a chemical approach. For this she requires to use

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Q: 91 (CDS-II/2010)
A woman desires to clean the surface’ of her gold ornaments by a chemical approach. For this she requires to use

question_subject: 

Science

question_exam: 

CDS-II

stats: 

0,21,13,21,8,2,3

keywords: 

{'gold ornaments': [0, 0, 1, 0], 'sodium thiosulphate solution': [0, 0, 1, 0], 'aqua regia': [0, 0, 1, 0], 'chemical approach': [0, 0, 1, 0], 'concentrated naoh': [0, 0, 1, 0], 'concentrated h2s04': [0, 0, 0, 1], 'surface': [1, 0, 0, 0]}

The woman desires to clean the surface of her gold ornaments using a chemical approach. The correct option for this purpose is Aqua regia (option 1). Aqua regia is a mixture of nitric acid and hydrochloric acid. It is highly acidic and is known for its ability to dissolve gold and other noble metals.

Let`s analyze the other options:

Option 2: Concentrated H2SO4 (sulfuric acid) is a strong acid, but it is not commonly used to clean gold surfaces. It is more commonly used for other chemical processes.

Option 3: Concentrated NaOH (sodium hydroxide) is a strong base, but it is not suitable for cleaning gold. While it can dissolve some metals, it does not have an effect on gold.

Option 4: Sodium thiosulphate solution is commonly used as a fixer in photography for removing excess silver from photographic prints. It does not have a direct effect on gold.

Therefore, option 1 (Aqua regia) is the most appropriate choice for cleaning the surface of gold ornaments.