Jamb Chemistry Past Questions For Year 2018
Question 21
The periodic classification is an arrangement of the elements
- A. atomic weights
- B. isotopic weights
- C. molecular weights
- D. atomic numbers
Question 22
The number of electrons in the valence shell of an element of atomic number 14 is?
- A. 1
- B. 2
- C. 3
- D. 4
Question 23
Suitable reagents for the laboratory preparation of nitrogen are
- A. sodium dioxonitrate(III) and ammonium chloride
- B. sodium trioxonitrate(V) and ammonium chloride
- C. sodium chloride and ammonium trioxonitrate(V)
- D. sodium chloride and ammonium di-ozonitrate(III)
Question 24
A quantity of electricity liberates 3.6g of Silver from its salt. What mass of aluminium Will be liberated from its salt by the same quantity of electricity? [Al = 27, Ag = 108].
- A. 2.7g
- B. 1.2g
- C. 0.9g
- D. 0.3g
Question 25
Methanoic acid mixes with water in all proportions and has about the same boiling point as water. Which of the following methods would you adopt to obtain pure water from a mixture of Sand, water and methanoic acid?
- A. Extractive distillation
- B. Filtration followed by distillation
- C. Neutralization with sodium hydroxide followed by distillation
- D. Neutralization with sodium hydroxide followed by filtration
