Limestone is a rock which often contains fossils - Edexcel - GCSE Chemistry - Question 5 - 2012 - Paper 1

The correct answer is B cement. Limestone is a key raw material in the production of cement, which is made by heating limestone and other materials.

When calcium carbonate (CaCO₃) is heated, it undergoes thermal decomposition to produce calcium oxide (CaO) and carbon dioxide (CO₂). The loss of carbon dioxide gas during this reaction results in a decrease in mass, which is why the mass of calcium oxide formed is less than the original mass of calcium carbonate. The reaction can be represented as:

$CaCO_3 (s) \rightarrow CaO (s) + CO_2 (g)$

The word equation for the reaction in step B, where calcium oxide reacts with water to form calcium hydroxide, is:

Calcium oxide + Water → Calcium hydroxide.

Opening a new limestone quarry can bring both benefits and challenges to the local community.

Advantages:

1. Economic Opportunities: The quarry can create jobs for local residents, contributing to the local economy.
2. Supply of Materials: Limestone is used in construction, which can support local building projects and industries.
3. Infrastructure Development: The establishment of a quarry may lead to improvements in local infrastructure, such as roads and transportation.

Disadvantages:

1. Environmental Impact: Quarrying activities can lead to habitat destruction, changes in land use, and loss of biodiversity.
2. Noise and Air Pollution: The operations can produce noise and dust, affecting the quality of life for local residents.
3. Community Displacement: In some cases, the establishment of quarries may lead to the displacement of communities or changes in land ownership, causing social upheaval.

Overall, while a new limestone quarry can provide economic benefits, it is essential to manage the environmental impacts and consider the opinions of the local community.