Question

The common, rock-forming mineral __________, which comprises the rock _______________, most readily dissolves in slightly-acidic groundwater?

a) Quartz, Granite
b) Calcite, Limestone
c) Feldspar, Basalt
d) Gypsum, Sandstone

Answer 1

Calcite, the mineral that comprises limestone, most readily dissolves in slightly-acidic groundwater.

Step-by-step explanation:

The common, rock-forming mineral that most readily dissolves in slightly-acidic groundwater is calcite, which comprises the rock limestone. This occurs because calcite, composed of calcium carbonate (CaCO3), reacts with acidic solutions to form calcium bicarbonate, which is soluble in water. The dissolution of calcite in limestone by groundwater can lead to the formation of caves and karst landscapes. It is interesting to note that fossils are common in limestone due to its formation in sedimentary environments often rich in living organisms. Whereas quartz, the main component of granite and quartzite, is very resistant to chemical weathering and therefore does not easily dissolve in acidic conditions.