Question

which statement describes how a basic coffee cup calorimeter works?
○ it measures the mass of a substance given the specific heat and temperature of water in a cup of known size.
○ it measures the density of a substance given the mass, specific heat, and temperature of water in a cup of known size.
○ it uses the mass and specific heat of water along with a pressure gauge to measure the gain or loss of energy when a substance is added.
○ it uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.

Explanation:

A coffee cup calorimeter measures heat transfer (energy gain/loss) during a reaction. It uses the mass and specific heat of water, and a thermometer to measure temperature change (ΔT). The formula \( q = mc\Delta T \) (where \( q \) is heat, \( m \) is mass, \( c \) is specific heat, \( \Delta T \) is temperature change) is applied. It does not measure mass/density of the substance (eliminating first two options) and uses a thermometer, not a pressure gauge (eliminating third option).

Answer:

It uses the mass and specific heat of water along with a thermometer to measure the gain or loss of energy when a substance is added.