Samarium is a metal. Large pieces of samarium react with cold water to produce hydrogen gas. (i) Complete Fig. 5.1 by drawing the apparatus to show how the volume of hydrogen gas is measured during this reaction. Fig. 5.1 (ii) The experiment is repeated using hot water instead of cold water. All other conditions stay the same. Describe how the rate of reaction changes when hot water is used. ................................................................................................................................... (iii) The experiment is repeated using powdered samarium instead of large pieces of samarium. All other conditions stay the same. Describe how the rate of reaction changes when powdered samarium is used. ...................................................................................................................................

Chemistry

IGCSE&ALevel

CAIE

Exam No：0620_m24_qp_32 Year：2024 Question No：5(c)

Answer:

11.5.1. State that the bonding in alkenes includes a double carbon–carbon covalent bond and that alkenes are unsaturated hydrocarbons

11.5.2. Describe the manufacture of alkenes and hydrogen by the cracking of larger alkane molecules using a high temperature and a catalyst

11.5.3. Describe the reasons for the cracking of larger alkane molecules

11.5.4. Describe the test to distinguish between saturated and unsaturated hydrocarbons by their reaction with aqueous bromine

11.5.5. State that in an addition reaction only one product is formed

11.5.6.1. bromine or aqueous bromine

11.5.6.2. hydrogen in the presence of a nickel catalyst

11.5.6.3. steam in the presence of an acid catalyst and draw the structural or displayed formulae of the products