CBSE 11TH CHEMISTRY - Online Test
Q1. The oxidation number of oxygen in most compounds is
Answer : Option D
Explaination / Solution:
Oxygen is the most electronegative element. Oxygen have 6 electrons in its outermost shell and to gain noble gas configuration oxygen have to take 2 more electrons.
Q2. Calorimetry is a branch of science dealing with
Answer : Option B
Explaination / Solution:
Calorimetry is a branch of science dealing with measuring the amount of energy transferred as heat
Q3. According to IUPAC nomenclature for elements with Z greater than 100,the root 'sept' corresponds to the digit:
Answer : Option B
Explaination / Solution:
Sept is for 7.
Numerical 0 1 2 3 4 5 6 7 8 9
roots nil un bi tri quad pent hex sept oct en
Q4. Emission spectrum of a material results from the material's (atom or molecules)
Answer : Option A
Explaination / Solution:
The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an atom or molecule making a transition from a high energy state to a lower energy state. The photon energy of the emitted photon is equal to the energy difference between the two states. There are many possible electron transitions for each atom, and each transition has a specific energy difference. This collection of different transitions, leading to different radiated wavelengths, make up an emission spectrum.
Q5. Nitrogen dioxide (NO2) causes :
Answer : Option A
Explaination / Solution:
Nitrogen dioxide is responsible for acute respiratory disease in children. It also causes irritating red haze in traffic and congested places, damages leaves of plants, retard rate of photosynthesis, toxicity to living tissues and harm to textile fibres and metals.
Q6. Dihydrogen is used in fuel cells for generating electrical energy because
Answer : Option C
Explaination / Solution:
The fuel cell was invented in 1839 by Welsh lawyer Sir William Robert Grove. It takes in Hydrogen and Oxygen from the air and puts out electricity, heat, and water. It doesn't use fossil fuels and it doesn't produce greenhouse gases and so it should be the ideal solution to providing distributed or portable electrical power.
Q7. Bond angle helps us in
Answer : Option A
Explaination / Solution:
Bond angles also contribute to the shape of a molecule. Bond angles are the angles between adjacent lines representing bonds. The bond angle can help differentiate between linear, trigonal planar, tetraheral, trigonal-bipyramidal, and octahedral. The ideal bond angles are the angles that demonstrate the maximum angle where it would minimize repulsion, thus verifying the VSEPR theory.
Q8. One of the following is the rarest of all alkaline earth metals
Answer : Option C
Explaination / Solution:
Ra is found in Uranium and thorium ores in trace amounts as small as a seventh of a gram per ton of uraninite so it is rarest of all alkaline earth metals
Q9. Covalent bonds are formed with other carbon atoms due to
Answer : Option D
Explaination / Solution:
Catenation is the linkage of atoms of the same element into longer chains.Catenation occurs most readily in carbon, which forms covalent bonds with other carbon atoms to form longer chains and structures. This is the reason for the presence of the vast number of organic compounds in nature.
Q10. Significant figures are
Answer : Option A
Explaination / Solution:
Significant digits are certain digits that have significance or meaning to certain digits in a number . Such digits help scientists to use them with more precise information about measurement and other numeric data. These digits also help them in rounding off very large or very small number
