Chemistry
In the molecule of water, oxygen atom has:
- One shared pair of electrons.
- Three shared pairs of electrons.
- Two lone pairs of electrons.
- One lone pair of electrons
Answer
Two lone pairs of electrons
Reason — Water contains two hydrogen atoms and one oxygen atom. The hydrogen atom [1] has one electron in it's valence shell while the oxygen atom [2, 6] has 6 electrons in it's valence shell. Two hydrogen atom share one electron each and two unshared pairs of electrons are left as lone pairs as shown in the diagram below :
Related Questions
Ammonia gas is collected by downward displacement of air since ammonia is:
- very slightly soluble in water.
- heavier than air.
- lighter than air.
- insoluble in water.
Which of the following would occupy 22.4 litres at S.T.P.?
(1) 32g of oxygen gas
(2) 2 moles of hydrogen gas
(3) 6.022 x 1023 molecules of ammonia
- 1 & 2
- 1 & 3
- 2 & 3
- 1, 2 & 3
[Atomic weights: O = 16, H = 1, N = 14]
A mineral from which the metal can be extracted economically and conveniently is known as:
- Matrix
- Ore
- Flux
- Alloy
The following sketch represents the electroplating of an Iron cup with Nickel metal. Study the diagram and answer the following questions:
(a) During electroplating the iron cup is placed at the cathode. Why?
(b) Name the ion that must be present in the electrolyte.
(c) State one condition that is necessary to ensure that the deposit is smooth, firm and even.
(d) Write the reaction taking place at the cathode.
(e) What change would you observe at the anode?