(a) What happens when baking soda is added to lemon juice?
(b) Is digestion a chemical change?
[3 MARKS]
(a) What happens when baking soda is added to lemon juice?
(b) Is digestion a chemical change?
[3 MARKS]
(a) Explanation: 2 Marks
(b) Explanation: 1 Mark
(a) When baking soda is added to lemon juice, a chemical change occurs. In this reaction, a new substance is formed which is carbon dioxide along with the evolution of heat. It is a chemical change and the reaction is irreversible.
The equation for the reaction is as follows:
Sodium Bicarbonate + Citric acid → Sodium Citrate + Carbon dioxide + Water + Heat
(b) Food is chemically digested by enzymes. Once food has been broken down, the nutrients are sent into the bloodstream where they find their way into the liver. Food undergoes many chemical changes before being absorbed by the body. Hence digestion of food is a chemical change as the complex substances that we eat is changed into simpler substances (new products).
(a) Explanation: 2 Marks
(b) Explanation: 1 Mark
(a) When baking soda is added to lemon juice, a chemical change occurs. In this reaction, a new substance is formed which is carbon dioxide along with the evolution of heat. It is a chemical change and the reaction is irreversible.
The equation for the reaction is as follows:
Sodium Bicarbonate + Citric acid → Sodium Citrate + Carbon dioxide + Water + Heat
(b) Food is chemically digested by enzymes. Once food has been broken down, the nutrients are sent into the bloodstream where they find their way into the liver. Food undergoes many chemical changes before being absorbed by the body. Hence digestion of food is a chemical change as the complex substances that we eat is changed into simpler substances (new products).
