(d) How are Saprophytes different from Parasites?
You are provided with three samples X, Y and Z. Sample X turns orange in Benedict's
solution on heating. Sample Y turns blue-black in iodine and Sample Z turns yellow in
concentrated nitric acid. Identify the samples X, Y and Z. Also write the nutritional
importance of sample X and Z
Answers
Explanation:
17. (a) Barium chloride reacts with aluminium sulphate to give aluminium chloride and barium sulphate.
(i) State the type of reaction.
(ii) Translate the above statement into a balanced chemical equation.
(b) A metal ‘X’ acquires a green colour coating on its surface on exposure to air.
(i) Identify the metal ‘X’ and name the process responsible for this change.
(ii) Name and write the chemical formula of the green colour coating formed on the surface of the metal.
18. 2g of Ferrous Sulphate crystals are heated in a boiling tube.
(i) State the colour of Ferrous Sulphate crystals both before heating and after heating.
(ii) Name the gases produced during heating.
(iii) Write the chemical equation for the reaction.
(b) Describe an activity to show a decomposition reaction in which light is used to decompose a reactant.
Write the chemical equation of the reaction and state one of its uses.
19. (a)Why is it essential to balance a chemical equation?
(b) With the help of a chemical reaction, explain the decomposition of lead nitrate.
(c)Can rusting of iron take place in distilled water? Give a reason.
(d)Give two methods to prevent rancidity.
(e) How will you test for the gas which is liberated when HCl reacts with an active metal?