Hydrogen — Prelims Questions

Which of the following statements about hydrogen is incorrect?

Which of the following methods is used for the removal of permanent hardness of water?

Which of the following hydrides is an example of an electron-deficient hydride?

What is the oxidation state of hydrogen in $NaH$ and $HCl$ respectively?

Which of the following statements is true regarding the structure of hydrogen peroxide ($H_2O_2$)?

In the Bosch process for hydrogen production, what is the role of the water-gas shift reaction?