Chemistry Past Questions And Answers
Two elements, X and Y are in the same group on the periodic table because they both have the same
- A. number of electronic shells
- B. number of valence electrons
- C. atomic size
- D. atomic number
What is the chemical formula of rust, which is formed on the surface of iron in the presence of oxygen and moisture?
- A. Fe3O4
- B. FeO
- C. Fe(OH)3
- D. Fe2O3
A given volume of oxygen diffused through a porous partition in 8 seconds. How long would it take the same volume of carbon (IV) oxide to diffuse under the same condition? [C = 12.0, O = 16.0]
- A. 5.8 seconds
- B. 6.8 seconds
- C. 9.4 seconds
- D. 11.0 seconds
8g of CH4 occupies 11.2 at S.T.P. What volume would 22g of CH3CH2CH3 occupy under the same condition?
- A. 3.7dm^3
- B. 11.2dm^3
- C. 22.4dm^3
- D. 33dm^3
Which of the following acids would readily react with CaCO3 to liberate CO2?
- A. CH3COOH
- B. H2SO4
- C. H2SO3
- D. HNO3
Which of the following statements is correct about ionization energy? It
- A. decreases across the periods
- B. results in the formation of an anion
- C. causes Metalic nuclei to disintegrate
- D. decreases down the group
Which of the following equipment is not used to detect radioactivity?
- A. Wilson cloud chamber
- B. Geiger- muller counter
- C. Mass spectrometer
- D. Photographic plate
The following compounds will decompose on heating except
- A. NaHCO3
- B. K2CO3
- C. MgCO3
- D. ZnCO3
The octane number of a fuel whose performance is the same as that of a mixture of 55 g of 2,2,4- trimethly pentane and 45 g of n-heptane is ?
- A. 45
- B. 55
- C. 80
- D. 100
How many bonding pair are present in carbon(iv)oxide?
- A. 4
- B. 3
- C. 2
- D. 1