Question

why is freshly prepared lime water used in an experiment to demonstrate evolution of CO2 during respiration

Answer 1

• Respiration is the chemical process by which oxygen is consumed and breakdown of glucose is done and subsequently carbon dioxide is produced along with heat.

• The freshly prepared lime water turns to be milky when carbon dioxide is passed through it.

• This milky lime water shows that carbon dioxide was produced during respiration.

Answer 2

Answer:

suppose the lime water is 1week old the ca(oh)2 reacts with co2 of atmosphere and turns caco3(milky) and it reacts with co2 and forms ca(hco3)2which can't turn milky because ca(hco3)2 is soluble in water

ca(oh)2 + co2 ----> caco3 + h2o

caco3 +h2o +co2---->ca(hco3)2