Chemistry - Online Test
Q1. 0.023 g of sodium metal is reacted with of water. The pH of the resulting solution is ______.
Answer : Option A
Explaination / Solution:
Moles of NaOH formed = 0.023/23 =0.001 Conc of NaOH=0.001x1000/100 =0.01 pOH=-log[OH-] =2 pH=14-2=12
Q2. Which of the following is soluble in turpentine oil?
Answer : Option D
Explaination / Solution:
Oxygen is soluble in turpentile oil.
Q3. Which branched chain isomer of the hydrocarbon with molecular mass 72u gives only one isomer of mono substituted alkyl halide?
Answer : Option C
Explaination / Solution:
Since we are getting monosubstituted alkyl halide so it is neopentane.
Q4. The exhibition of various oxidation states by an element is also related to the outer orbital electronic configuration of its atom. Atom(s) having which of the following outermost electronic configurations will exhibit more than one oxidation state in its compounds.
Answer : Option C
Explaination / Solution:
(3d24s2) is the configuration of transition element which shows variable oxidation state.
Q5. The coordination number of AB having rock salt geometry is
Answer : Option C
Explaination / Solution:
NaCl has rock salt structure. Coordination No. is 6.
Q6. The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on its outer shell electrons is:
Answer : Option B
Explaination / Solution:
Screening effect order follows s>p>d>f, this due to the nature of the orbitals involved. s-orbitals are least diffused and the two electrons in s-orbitals provide greatest shielding of the nuclear charge to the outermost electron. The diffused character increases in the order p>d>f. f-orbitals are so diffused that fourteen electrons inside them provide virtually no screening of the nuclear charge.
Q7. Which of the following gases is not a green house gas?
Answer : Option C
Explaination / Solution:
CO is not a green-house gas?
Q8. An atom of an element contains 29 electrons and 35 neutrons. The number of protons are:
Answer : Option B
Explaination / Solution:
In a atom no. of protons = no. of electrons i.e. P = E while this is not true in case of ions.
So number of protons in given atom is 29.
Q9. Ni2+ in traces can be tested using
Answer : Option B
Explaination / Solution:
Ni forms complex with DMG which is red in color.
Q10. Elements of which of the following group(s) of periodic table do not form hydrides.
Answer : Option C
Explaination / Solution:
Elements of group 7, 8, 9 of d – block do not form hydrides at all. This inability of metal, of group 7, 8, 9 of periodic table to form hydrides is referred to as hydride gap of d – block.
