Post Utme Chemistry Questions
Question 151:
Calculate the molecular formula of a compound with empirical formula \(\mathrm{CH}_{2} \mathrm{O}\) and relative molecular mass 120<br/>\((\mathrm{C}=12, \mathrm{O}=16, \mathrm{H}=1)\)
- A \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{2}\)
- B \(\mathrm{C}_{1} \mathrm{H}_{3} \mathrm{O}_{4}\)
- C \(\mathrm{C}_{3} \mathrm{H}_{16} \mathrm{O}_{\text {a }}\)
- D \(\mathrm{C}_{3} \mathrm{H}_{2} \mathrm{O}_{3}\)
Question 152:
A mixture of sugar and sulphur can be separated by ____________
- A Dissolution in water, evaporation and filtration
- B Filtration, evaporation and dissolution in water
- C Dissolution in water, filtration and evaporation
- D Evaporation, dissolution in water and filtration<br/>CHEMISTRY
Question 153:
Which of the following is a physical change ____________
- A Freezing ice cream
- B Dissolving calcium in water
- C Burning kerosene
- D Exposing white phosphorus to air
Question 154:
The percentage of water of crystallization in \(\mathrm{ZnSO}_{4} .7 \mathrm{H}_{2} \mathrm{O}\) is ____________
- A \(33 \%\)
- B \(44 \%\)
- C \(55 \%\)
- D \(87 \%\)
Question 155:
A gas exert pressure on its container because ____________
- A The molecules of gas collide with thewall of the container
- B Some of the molecules are moving faster than others
- C Of the collisions of the molecules with each other
- D Of the mass of the molecules of the gas