When hydrogen gas is passed over heated copper (II) oxide, copper and steam are formed. Write the balanced chemical equation for this reaction and state

(i) the substance oxidised and

(ii) the substance reduced in the reaction. (2014)

What is meant by rancidity? How it can be prevented?

Write true or false for the following statements:

Keeping food in airtight containers helps to slow down oxidation.

A student adds 4 mL of acetic acid to a test tube containing 4 ml of distilled water. He then shakes the test tube and leaves it to settle. after about, 10 minutes he observes:

A student prepared an aqueous solution of CuS04 in beaker X and an aqueous solution of FeS04 in beaker Y. He then dropped some iron pieces in beaker X and some zinc pieces in beaker Y. after about 10 hours he observed that the solutions in X and Y respectively appear:

Describe two examples of different oxidations of ethanol. Name the products obtained in each case.

What is an oxidizing agent? What happens when an oxidizing agent is added to propanol? Explain with the help of a chemical equation.

Name the oxidising agent used for the conversion of ethanol to ethanoic acid. Distinguish between ethanol and ethanoic acid on the basis of (i) litmus test, (ii) reaction with sodium carbonate.

Name the oxidizing agent used for the conversion of ethanol to ethanoic acid. Distinguish between ethanol and ethanoic acid on the basis of (i) litmus test, (ii) reaction with sodium hydrogen carbonate.

An organic compound 'X' on heating with cone. H₂SO₄ forms a compound 'Y' which on addition of one molecule of hydrogen in the presence of nickel forms a compound 'Z'. One molecule of compound 'Z' on combustion forms two molecules of C0₂ and three molecules of H₂0. Identify giving reasons the compounds 'X', 'Y' and 'Z'. Write the chemical equations for all the chemical reactions involved.