datavorous/entrance-exam-dataset huggingface dataset:
Consider two plots, where plot 'X' is having less species compared to plot 'Z'. Select the true statement regarding X and Z.

Options:
A Plot 'X' shows less year to year variation in total biomass
B Plot 'Z' is less resistant to natural disturbance
C Plot 'X' has more productivity than plot 'X'
D Plot 'Z' has more productivity than plot 'X'

The correct answer is:
Plot 'Z' has more productivity than plot 'X'

Solution:
Biodiversity is can be said to be the measure of the complexity of interactions between organisms and the ecosystem. The greater the number of species results in more interactions which supports biodiversity. Also, helps an ecosystem or habitat to survive and adapt to environmental stress. These will increase the biomass of the particular ecosystem thus, making productivity high. Hence, the plot Z will have more productivity than plot X.

Topic: Biology, Ecosystem, NEET
Consider two rods of the same length and different specific heats $\left(S_1, S_2\right)$, conductivities $\left(K_1, K_2\right)$ and area of cross sections $\left(A_1, A_2\right)$ and both having temperature $T_1$ and $T_2$ at their ends. If the rate of loss of heat due to conduction is equal then:

Options:
A $K_1 A_1=K_2 A_2$
B $\frac{K_1 A_1}{S_2}=\frac{K_2 A_2}{S_1}$
C $K_2 A_1=K_1 A_2$
D $\frac{K_2 A_1}{S_2}=\frac{K_1 A_2}{S_1}$

The correct answer is:
$K_1 A_1=K_2 A_2$

Solution:
Rate of conduction of heat is given as
$\frac{\Delta \mathrm{Q}}{t}=\frac{K A}{L}\left(T_2-T_1\right)$
According to the question
$\begin{aligned}
& \frac{\Delta Q_1}{\Delta t}=\frac{\Delta Q_2}{\Delta t} \\
& \Rightarrow \frac{K_1 A_1}{L}\left(T_1-T_2\right)=\frac{K_1 A_1}{L}\left(T_1-T_2\right) \\
& \Rightarrow K_1 A_1=K_2 A_2
\end{aligned}$

Topic: Physics, Thermal Properties of Matter, NEET, NEET 2002
Consider two solid spheres of radii R1=1 m,R2=2 m and masses M1 and M2, respectively. The gravitational field due to sphere 1 and 2 are shown. The value of M1M2 is:

Options:
A 23
B 16
C 12
D 13

The correct answer is:
16

Solution:
3=GM222
2=GM112
∴32=14M2M1
M1M2=16

Topic: Physics, Gravitation, NEET
Considering Ellingham diagram, which of the following metals can be used to reduce alumina?

Options:
A Mg
B Zn
C Fe
D Cu

The correct answer is:
Mg

Solution:
Mg has more (−ve)ΔG value than alumina.

So it will be in the lower part of Ellingham diagram. Metals which has more (−ve)ΔG value can reduce those metal-oxide which has less (−ve)ΔG value.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET, NEET 2018
Considering Ellingham diagram, which of the following metals can be used to reduce alumina?

Options:
A Mg
B Zn
C Fe
D Cu

The correct answer is:
Mg

Solution:
The metal which is more reactive than ‘Al’ can reduce alumina. ‘Mg’ is more reactive than Al, so it can be used.
As Zn, Fe and Cu are less reactive than 'Al' so they cannot reduce alumina.

Topic: Chemistry, General Principles and Processes of Isolation of Metals, NEET
Considering entropy (S) as a thermodynamic parameter, the criteria for the spontaneity of any process is

Options:
A ∆Ssystem+∆Ssurroundings>0
B ∆Ssystem-∆Ssurroundings>0
C ∆Ssystem>0 only
D ∆Ssurroundings>0 only

The correct answer is:
∆Ssystem+∆Ssurroundings>0

Solution:
In the reversible process
âSsystem+âSsurroundings=0
Hence, the system is present in equilibrium
(i.e., it is not a spontaneous process)
While in the irreversible process
âSsystem+âSsurroundings>0

Topic: Chemistry, Thermodynamics (C), NEET
Considering entropy (S) as a thermodynamic parameter, the criterion for the spontaneity of any process is:

Options:
A $\Delta \mathrm{S}_{\text {system }}+\Delta \mathrm{S}_{\text {surrounding }}>0$
B $\Delta \mathrm{S}_{\text {system }}-\Delta \mathrm{S}_{\text {surrounding }}>0$
C $\Delta \mathrm{S}_{\text {System }}>0$ only
D $\Delta \mathrm{S}_{\text {Surroundings }}>$ only

The correct answer is:
$\Delta \mathrm{S}_{\text {system }}+\Delta \mathrm{S}_{\text {surrounding }}>0$

Solution:
According to Second Law of Thermodynamics, for a spontaneous process, total change in entropy (system + surrounding) should be positive.
Related Theory
(Ref. to Fig. 28.1)
For the latter two cases, the temperature at which the spontaneity changes will be determined by the relative magnitudes of $\triangle S$ and $\Delta H$.

Topic: Chemistry, Thermodynamics (C), NEET, NEET 2004
Considering $\mathrm{H}_2 \mathrm{O}$ as a weak field ligand, the number of unpaired electrons in $\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$ will be:
(atomic number of $\mathrm{Mn}=25$ )

Options:
A three
B five
C two
D four

The correct answer is:
five

Solution:
$\mathrm{H}_2 \mathrm{O}$ is a weak ligand. Thus, there will be no pairing of electron and forms high spin complex.
Thus, no. of unpaired $e^{-}=5$
Related Theory
$\left[\mathrm{Mn}\left(\mathrm{H}_2 \mathrm{O}\right)\right]^{2+}$ has octahedral geometry where the central atom are surrounded by 6 other molecules or ligands that are systematically arranged.

Topic: Chemistry, Coordination Compounds, NEET, NEET 2004
Considering the parameters such as bond dissociation enthalpy, electron gain enthalpy, and hydration enthalpy, compare the oxidizing power of F2and Cl2.

Options:
A F2is a stronger oxidizing agent due to its higher bond dissociation enthalpy.
B F2is a stronger oxidizing agent due to its higher electron gain enthalpy.
C Cl2is a stronger oxidizing agent due to its higher bond dissociation enthalpy.
D Cl2is a stronger oxidizing agent due to its higher electron gain enthalpy.

The correct answer is:
F2is a stronger oxidizing agent due to its higher electron gain enthalpy.

Solution:
Correct Option is : (B)
F2is a stronger oxidizing agent due to its higher electron gain enthalpy.

Topic: Chemistry, p Block Elements (Group 13 & 14), NEET
Considering the state of hybridisation of carbon atoms, find out the molecule among the following which is linear.

Options:
A $\mathrm{CH}_3-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_3$
B $\mathrm{CH}_2=\mathrm{CH}-\mathrm{CH}_2-\mathrm{C} \equiv \mathrm{CH}$
C $\mathrm{CH}_3-\mathrm{CH}_2-\mathrm{CH}_2-\mathrm{CH}_3$
D $\mathrm{CH}_3-\mathrm{CH}=\mathrm{CH}-\mathrm{CH}_3$

The correct answer is:
$\mathrm{CH}_3-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_3$

Solution:
$\mathrm{H}_3 \mathrm{C}-\mathrm{C} \equiv \mathrm{C}-\mathrm{CH}_3$ is linear, because $\mathrm{C}_2$ and $\mathrm{C}_3$ are $s p$ hybridised.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET, NEET 2011 (Screening)
Considering the structure of the product formed from RSiCl3, which of the following statements is true?

Options:
A It consists of repeating units of (-Si(R)2O-).
B It is a linear polymer with no branching.
C The "R" groups are nitrogen-based substituents.
D It primarily consists of carbon-carbon bonds.

The correct answer is:
It consists of repeating units of (-Si(R)2O-).

Solution:
Correct Option is : (A)
It consists of repeating units of (-Si(R)2O-).

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Considering the structures of CO32–and HCO3–ions, which of the following statements is true?

Options:
A CO32–is a linear ion with all oxygen atoms arranged in a straight line.
B HCO3–is a symmetrical ion with equal bond lengths between carbon and oxygen.
C CO32–has a trigonal planar geometry with a delocalized negative charge.
D HCO3–has a tetrahedral geometry with the carbon atom at the center.

The correct answer is:
HCO3–has a tetrahedral geometry with the carbon atom at the center.

Solution:
Correct Option is : (D)
HCO3–has a tetrahedral geometry with the carbon atom at the center.

Topic: Chemistry, p Block Elements (Group 15, 16, 17 & 18), NEET
Considering the x-axis as the internuclear axis, which out of the following will not form a sigma bond and why? (a) 1s and 1s (b) 1s and 2px(c) 2pyand 2py(d) 1s and 2s

Options:
A 1s and 1s will not form a sigma bond because they have the same orientation.
B 1s and 2pxwill not form a sigma bond because they have different orientations along the x-axis.
C 2pyand 2pywill not form a sigma bond because they have the same orientation.
D 1s and 2s will not form a sigma bond because they have different orientations along the x-axis

The correct answer is:
1s and 2pxwill not form a sigma bond because they have different orientations along the x-axis.

Solution:
Correct Option is : (B)
1s and 2pxwill not form a sigma bond because they have different orientations along the x-axis.

Topic: Chemistry, Chemical Bonding and Molecular Structure, NEET
Consumption of which one of the following foods can prevent the disease associated with vitamin -A deficiency?

Options:
A Flavr-savr tomato
B Tobacco
C Golden rice
D Bt cotton

The correct answer is:
Golden rice

Solution:
Golden rice a variety of Oryza sativa is produced through the genetic engineering to biosynthesize beta carotene, a precursor of pro-vitamin A in the edible parts of rice. Golden rice is enriched by introducing three genes involved in the biosynthetic pathway for carotenoid. Thus golden rice is genetically engineered rice with greater vitamin A content.

Topic: Biology, Biotechnology and Its Applications, NEET
Consumption of which one of the following foods can prevent the kind of blindness associated with vitamin-A deficiency?

Options:
A Flaver savr tomato
B Canolla
C Golden rice
D Bt-brinjal

The correct answer is:
Golden rice

Solution:
Golden rice is a variety of Oryza sativa (rice) produced through genetic engineering to biosynthesize Beta-carotene, a precursor of vitamin-A in the edible part of rice (i.e., endosperm). The research that led to golden rice was conducted with the goal of helping children who suffer from vitamin-A deficiency. Because many children in countries where there is a dietary deficiency in vitamin-A rely on rice as a staple food, the genetic modification of rice to produce the vitamin-A precursor beta-carotene is seen as a simple and less expensive alternative to vitamin supplements.

Topic: Biology, Biotechnology and Its Applications, NEET, NEET 2012 (Screening)
Contagium vivum fluidum was proposed by

Options:
A D.J. Ivanowsky
B M.W. Beijerinck
C Stanley
D Robert Hook

The correct answer is:
M.W. Beijerinck

Solution:
Contagium vivum fluidum was proposed by M.W. Beijerinck.

Topic: Biology, Biological Classification, NEET
Containers A and B have same gases. Pressure, volume and temperature of A are all twice as that of B, then the ratio of number of molecules of A and B are

Options:
A 1 : 2
B 1 : 4
C 4 : 1
D 2 : 1

The correct answer is:
2 : 1

Solution:
For the two gases,
P A = 2P B
P A V A = n A RT A and P B V B = n B RT B
n A n B = P A V A RT A P B V B RT B = 2 P B Ã 2 V B 2 T B P B Ã V B T B = 2
The number of molecules are also in the ratio 2 : 1.

Topic: Chemistry, Hydrocarbons, NEET
Continuous addition of sugars in 'fed batch' fermentation is done to

Options:
A obtain antibiotics
B purify enzymes
C degrade sewage
D produce methane

The correct answer is:
purify enzymes

Solution:
A fed batch is a biotechnological batch process which is based on feeding of a growth limiting nutrient substrate to a culture. Continuous addition of sugars in fed batch fermentation is done to purify enzymes.

Topic: Biology, Microbes in Human Welfare, NEET, NEET 2011 (Screening)
Continuous bleeding from an injured part of the body is due to the deficiency of

Options:
A vitamin $\mathrm{A}$
B vitamin $B$
C vitamin $\mathrm{K}$
D vitamin $\mathrm{E}$

The correct answer is:
vitamin $\mathrm{K}$

Solution:
Vitamin $\mathrm{K}$ is a group of vitamins that the body needs for blood clotting, helping wounds to heal.
Related Theory:-
The effects of vitamin $K$ toxicity can include anaemia due to rupture of red blood cells and jaundice. Jaundice in new born can cause kernicterus

Topic: Biology, Biomolecules (B), NEET, NEET 2002
'Contractile vacuole' play important role in excretion in

Options:
A Amoeba
B Paramecium
C Hydra
D both A & B

The correct answer is:
both A & B

Solution:
The Endomembrane system in Eukaryotes consists of Endoplasmic reticulum, golgi complex, lysosomes and vacuoles as their functions are coordinated. The Vacuole is membrane bound space and it consists of sap, water, excretory product etc. It has a single membrane called as tonoplast. These vacuoles are called as contractile vacuole in Amoeba and Paramoecium. This is useful for excretion.

Topic: Biology, Excretory Products and their Elimination, NEET
Contraction of diaphragm during inhalation

Options:
A It decreases the volume of the thoracic chamber in the anteroposterior axis.
B It increases the volume of the thoracic chamber in the dorso-ventral axis.
C It increases the volume of the thoracic chamber in the anteroposterior axis.
D It decreases the volume of the thoracic chamber in the dorso-ventral axis.

The correct answer is:
It increases the volume of the thoracic chamber in the anteroposterior axis.

Solution:
Inspiration is initiated by the contraction of diaphragm which increases the volume of the thoracic chamber in the anteroposterior axis. The contraction of external intercostal muscles lifts up the ribs and the sternum causing an increase in the volume of the thoracic chamber in the dorso-ventral axis.

Topic: Biology, Breathing and Exchange of Gases, NEET
Contraction of diaphragm increases the volume of the thoracic chamber in the ......(A)...... axis while the contraction of external intercostal muscles increases the volume of the thoracic chamber in the .......(B)...... axis.

Options:
A A: antero-posterior, B: antero-posterior
B A: dorso-ventral, B: dorso-ventral
C A: antero-posterior, B: dorso-ventral
D A: dorso-ventral, B: antero-posterior

The correct answer is:
A: antero-posterior, B: dorso-ventral

Solution:
External intercostal muscles and diaphragm play an important role in the inspiration and expiration of gases. During inspiration, there is the movement of oxygen inside the lungs i.e. oxygen moves from high pressure to low pressure as the volume of the lung cavity is in an expanded state, and movement of gases follows Boyle's law. The contraction of external intercoastal muscles and diaphragm causes this increase. External intercostal muscles when contract they pull the ribs and sternum outwards and thus the increase of lung cavity is in dorso-ventral axis. When diaphragm contracts it is pulled downwards and thus the increase of lung cavity is in antero-posterior axis.

Topic: Biology, Breathing and Exchange of Gases, NEET
Contraction of the ventricle in the heart begins by the command from

Options:
A Chordae tendinae
B S.A. node
C Purkinje fibres
D A.V. node

The correct answer is:
S.A. node

Solution:
SA is the site of generation of the rhythmic cardiac impulse. AV node is a compact mass of myogenic fibres which receives an impulse from the SA node and transmits it to ventricles. Purkinje fibres are in contact with the contractile muscles of the ventricular walls. Chordae tendinae are the muscles which keep the AV valves in position.

Topic: Biology, Body Fluids and Circulation, NEET
Control of gene expression in prokaryotes takes place at the level of:

Options:
A DNA-replication
B Transcription
C Translation
D None of the above

The correct answer is:
Transcription

Solution:
Control of gene expression in prokaryotes takes place at the level of transcription when the codons are being transcribed from DNA.

Topic: Biology, Molecular Basis of Inheritance, NEET
Convergent evolution is illustrated by:

Options:
A rat and dog
B bacterium and protozoan
C starfish and cuttlefish
D dogfish and whale

The correct answer is:
dogfish and whale

Solution:
Convergent evolution occurs when species occupy similar ecological niches and adapt in similar ways in response to similar selective pressures. For example, Dogfish (Pisces) and whale (mammas) have acquired aquatic character though distantly related.
Rat and dog (mammals), bacterium and protozoan (unicellular), and starfish (mollusc) and cuttlefish (Echinodermata) show divergent evolution.
Related Theory
Sea stars do not have gills, scales, or fins. Sea stars live only in saltwater. Sea water, instead of blood, is actually used to pump nutrients through their bodies via a 'water vascular system. Hence, they are not considered as fish.

Topic: Biology, Evolution, NEET, NEET 2003
Conversion of glucose to glucose-6-phosphate, the first irreversible reaction of glycolysis, is catalyzed by:

Options:
A Aldolase
B Hexokinase
C Enolase
D Phosphofructokinase

The correct answer is:
Hexokinase

Solution:
Hexokinase.

In the first step of glycolysis, the glucose ring is phosphorylated. Phosphorylation is the process of adding a phosphate group to a molecule derived from ATP. As a result, at this point in glycolysis, 1 molecule of ATP has been consumed.

For enzyme hexokinase, Mg++ ions are used as activator.

Topic: Biology, Respiration in Plants, NEET, NEET 2019 (All India)
Conversion of isobutene into isobutyl alcohol can be possible with

Options:
A HOH/H⊕
B BH3 followed by H2O2/O-H
C Conc. H2SO4 followed by HOH
D All of these

The correct answer is:
BH3 followed by H2O2/O-H

Solution:
Conversion of isobutene into isobutyl alcohol can be possible with BH3 followed by H2O2/O-H i.e., hydroboration reaction

Topic: Chemistry, Hydrocarbons, NEET
Conversion of milk to curd improves its nutritional value by increasing the amount of

Options:
A Vitamin B12
B Vitamin A
C Vitamin D
D Vitamin E

The correct answer is:
Vitamin B12

Solution:
During the conversion of milk into curd, the amount of lactic acid increases in the sample due to the action of the lactic acid bacteria.
An increase in the amount of lactic acid is accompanied by the increase in Vitamin B12, thus improving the nutritional quality of the curd.

Topic: Biology, Microbes in Human Welfare, NEET, NEET 2018
Conversion of milk to curd improves its nutritional value by increasing the amount of

Options:
A Vitamin D
B Vitamin B12
C Vitamin A
D Vitamin E

The correct answer is:
Vitamin B12

Solution:
Conversion of milk to curd is done by Lactobacillus, which causes coagulation of milk and partial digestion of milk protein casein. It adds vitamin B12 and increases the nutritional quality of curd. Curd is also useful in controlling the growth of other disease-causing microbes in the stomach.

Topic: Biology, Microbes in Human Welfare, NEET
Conversion of NO2-â NH4+ is called ______ and is catalysed by______

Options:
A Nitrate assimilation, nitrate and nitrite reductase
B Nitrification, nitrate and nitrite reductase
C Ammonification, glutamate dehydrogenase
D Denitrification, transaminase

The correct answer is:
Nitrate assimilation, nitrate and nitrite reductase

Solution:
Plant absorbs nitate from soil but cannot utilize it, and it gets converted to ammonium ion for formation of amino acid. This process is known as nitrate assimilation and is catalysed by enzyme nitrate and nitrite reductase.

Topic: Biology, Mineral Nutrition, NEET
Conversion of prothrombin to thrombin during clotting requires

Options:
A Vitamin K
B fibrin
C thrombokinase
D heparin

The correct answer is:
thrombokinase

Solution:
Thrombokinase or thromboplastin is an enzyme which is a mixture of phospholipid and the tissue factor found in the plasma. It is released from the blood platelets and helps in the conversion of prothrombin to thrombin when the process of clotting begins. Fibrin is formed from fibrinogen during the process of coagulation. Heparin is antagonistic to fibrin and thrombokinase and acts as an anticoagulant.

Topic: Biology, Body Fluids and Circulation, NEET
Conversion of pyruvic acid into ethyl alcohol is facilitated by:

Options:
A Carboxylase
B Dehydrogenase
C Decarboxylase and dehydrogenase
D Phosphatase

The correct answer is:
Decarboxylase and dehydrogenase

Solution:
In fermentation, by yeast, the incomplete oxidation of glucose is achieved under anaerobic conditions by sets of reactions where pyruvic acid is converted to CO2 and ethanol. The enzymes, pyruvic acid decarboxylase and alcohol dehydrogenase catalyse these reactions.

Topic: Biology, Respiration in Plants, NEET
Convert 1 km to (i) mm and (ii) pm

Options:
A (i)1015mm and (ii)106pm
B (i)109mm and (ii)1010pm
C (i)106mm and (ii)1015pm
D (i)108mm and (ii)1012pm

The correct answer is:
(i)106mm and (ii)1015pm

Solution:
Correct Option is : (C)
(i)106mm and (ii)1015pm

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Convert 1 mg to (i) kg and (ii) ng

Options:
A (i)108kg and (ii)106ng
B (i)106kg and (ii)10-6ng
C (i)108kg and (ii)106ng
D (i)10-6kg and (ii)106ng

The correct answer is:
(i)10-6kg and (ii)106ng

Solution:
Correct Option is : (D)
(i)10-6kg and (ii)106ng

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Convert 1 mL to (i) L and (ii) dm3

Options:
A (i)10-3L and (ii)10-3dm3
B (i)103L and (ii)103dm3
C (i)10-3L and (ii)104dm3
D (i)104L and (ii)10-3dm3

The correct answer is:
(i)10-3L and (ii)10-3dm3

Solution:
Correct Option is : (A)
(i)10-3L and (ii)10-3dm3

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Convert the following into basic units: (i) 28.7 pm (ii) 15.15 pm and (iii) 25365 mg

Options:
A (i) 2.87×10-14m (ii) 1.515×10-10m and (iii) 2.5365×10-6kg
B (i) 2.87×10-11m (ii) 1.515×10-11m and (iii) 2.5365×10-2kg
C (i) 2.87×10-9m (ii) 1.515×10-13m and (iii) 2.5365×10-4kg
D (i) 28.7×10-11m (ii) 1.515×10-11m and (iii) 253.65×10-2kg

The correct answer is:
(i) 2.87×10-11m (ii) 1.515×10-11m and (iii) 2.5365×10-2kg

Solution:
Correct Option is : (B)
(i) 2.87×10-11m (ii) 1.515×10-11m and (iii) 2.5365×10-2kg

Topic: Chemistry, Some Basic Concepts of Chemistry, NEET
Coordination compounds are widely present in which of the following?

Options:
A Plants only
B Minerals only
C Animal worlds only
D Minerals, plants, and animal worlds

The correct answer is:
Minerals, plants, and animal worlds

Solution:
Coordination compounds are widely present in minerals, plants, and animal worlds.

Topic: Chemistry, Coordination Compounds, NEET
Coordination no. of atom residing in octahedral void is:

Options:
A 2
B 4
C 6
D 8

The correct answer is:
6

Solution:
Correct Option is : 3
6

Topic: Chemistry, Solid State, NEET
Coordination number of Ni in [Ni(C2O4)3]4- is

Options:
A 3
B 6
C 4
D 2

The correct answer is:
6

Solution:
C2O42-→ bidentate ligand.
3 molecules attached from two sides with Ni makes co-ordination number 6.

Topic: Chemistry, Coordination Compounds, NEET
Copper can be reduced from acidic copper sulphate solution by

Options:
A Silver
B Iron
C Carbon
D Lead

The correct answer is:
Iron

Solution:
CuSO4+Fe→Cu+FeSO4
Oxidation potential of Fe is greater than Cu .

Topic: Chemistry, d and f Block Elements, NEET
Copper crystallises in a face-centred cubic lattice with a unit cell length of $361 \mathrm{pm}$. What is the radius of copper atom in pm ?

Options:
A 128
B 157
C 181
D 108

The correct answer is:
128

Solution:
In case of face-centred cubic lattice,
$$
\text { radius }=\frac{\sqrt{2} a}{4}
$$
$\therefore$ Radius of copper atom ( lattice)
$$
=\frac{\sqrt{2} \times 361}{4}=128 \mathrm{pm} .
$$

Topic: Chemistry, Solid State, NEET, NEET 2009 (Screening)
Copper crystallizes in an FCC unit cell with cell edge of 3.608×10−8 cm. The density of copper is 8.92 g/cm3, Calculate the atomic mass of copper.

Options:
A 63.1 u
B 65 u
C 60 u
D 31.55 u

The correct answer is:
63.1 u

Solution:
The number of effective atoms in a FCC unit cell, Z=4 atoms
M= d× N0× a3 Z
Where,

M is atomic mass of copper

d is density of copper= 8 .92 g/cm3,

N0 is the Avogadro number =6.022× 1023 mol-1
a is the edge length =3.608×10−8cm

Substituting the values in the formula,

⇒M=8.92g/cm3×6.022×1023atom/mol×(3.608×10−8cm)34 atoms

⇒M=63.1 g/mol

Atomic mass of copper =63.1 u

Topic: Chemistry, Solid State, NEET, NEET 2022 (Phase 1)
Copper crystallizes in fcc with a unit cell length of 361 pm. What is the radius of copper atom?

Options:
A 127 pm
B 157 pm
C 181 pm
D 108 pm

The correct answer is:
127 pm

Solution:
For FCC the atoms touch each other along the face â diagonal
r=2a4=2Ã3614
r =127 pm

Topic: Chemistry, Solid State, NEET