Question
Many transition metals are useful as __ in reactions . What word completes the sentence?
Answer
4.1
(251 Votes)
Grace
Master · Tutor for 5 years
Answer
Catalysts
Explanation
The question is about transition metals and their role in reactions. Transition metals are elements found in the middle of the periodic table, named so for their electron configuration, where the transition electrons are added to the inner "d" subshell , closer to the nucleus, thus their properties vary less regularly going across the periods, unlike main group elements. The special characteristics of transition metals come from partially filled d orbitals which enable them to serve a very particular role. In chemical reactions, transition metals often act as catalysts. A catalyst is a substance that speeds up a chemical reaction, but it is not consumed by the reaction; hence it can be recovered chemically unchanged at the end of the reaction. They offer a platform for the reactants to come together and react more easily by providing an alternative reaction pathway of lower activation energy. Some common transition metal catalysts are Iron in the Haber process for ammonia synthesis, Nickel in hydrogenation of alkenes and Vanadium(V) oxide in the Contact process for the manufacture of sulphuric acid. So the word that completes the sentence is Most likely 'catalysts'.