How many lone pairs of electron are there on the central atom of the H2O molecules?
- A. 1
- B. 2
- C. 3
- D. 4
The nucleus of the isotope tritium, contains?
- A. two neutrons with no protons
- B. one neutron and one protons
- C. two neutrons and one proton
- D. two neutrons, one proton and one electron
An increase in temperature causes an increase in pressure of a gas in a fixed volume due to an increase in the?
- A. number of molecules of the gas
- B. density of the gas molecules
- C. number of collisions between the gas molecules
- D. number of collisions between the gas molecules and the walls of the container
If 100 cm3 of oxygen pass through a porous plug in 50 seconds, the time taken for the same volume of hydrogen to pass through the same porous plug is?
(O = 16, H = 1)
- A. 10.0 s
- B. 12.5 s
- C. 17.7 s
- D. 32.0 s
Which of the following is a measure of the average kinetic energy of the molecules of a substance?
- A. Volume
- B. Mass
- C. pressure from age grades
- D. Temperature
A given mass of gas occupies 2 dm3 at 300k. At what temperature will its volume be doubled keeping the pressure constant?
- A. 400 k
- B. 480 k
- C. 550 k
- D. 600 k
wH2SO4 + xAI(OH)3 → yH2O + = zAI2(SO4)3. The respective values of w.x.y and z in the equation above are?
- A. 2,2,5 and 1
- B. 3,2,5 and 2
- C. 3,2,6 and 1
- D. 2,2,6 and 2
How many moles of (H+) are there in 1 dm3 of 0.5 M solution of H2SO4?
- A. 2.0 moles
- B. 1.0 moles
- C. 0.5 mole
- D. 0.25 mole
There is a large temperature interval between the melting point and the boiling point of a metal because?
- A. metals have very high melting points
- B. metals conduct heat very repaidly
- C. melting does not break the metalic bond but boiling does
- D. the crystal lattice of metals is easily broken