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In a vessel, the gas is at a pressure P. If the mass of all the molecules is halved and their speed is doubled, then the resultant pressure will be:

  • Option 1)

    4P

  • Option 2)

    2P

  • Option 3)

    P

  • Option 4)

    \frac{P}{2}

 
Pressure of a gas if mass is halved and speed is doubled pressure becomes 2P Option 1) 4P Option 2) 2P Option 3) P Option 4)

A reaction having equal energies of activation for forward and reverse reactions has:

  • Option 1)

    \DeltaH = \DeltaG = \DeltaS=0

  • Option 2)

    \DeltaS = 0

  • Option 3)

    \DeltaG = 0

  • Option 4)

    \DeltaH = 0

 
Option 1) H = G = S=0 Option 2) S = 0 Option 3) G = 0 Option 4) H = 0
Engineering
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The most popularly known blood grouping is the ABO grouping. It is named ABO and not ABC, because "O" in it refers to having:

  • Option 1)

    overdominance of this type on the genes for A and B types

  • Option 2)

    one antibody only - either anti-A or anti-B on the RBCs

  • Option 3)

    no antigens A and B on RBCs

  • Option 4)

    other antigens besides A and B on RBCs

 

3 option

 

Engineering
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The Gibbs energy for the decomposition of Al2O3 at 500oC is as follows:

\frac{2}{3}\text{Al}_{2}\text{O}_{3}\rightarrow \frac{4}{3}\text{Al}+\text{O}_{2};

\Delta_{\text{r}}\text{G}=+960 \text{kJ} \text{mol}^{-1}.

The potential difference needed for the electrolytic reduction of aluminium oxide (Al2O3) at 500oC is at least:

  • Option 1)

    3.0 V

  • Option 2)

    2.5 V

  • Option 3)

    5.0 V

  • Option 4)

    4.5 V

 
Engineering
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The enthalpy of fusion of water is 1.435 kcal/mol. The molar entropy change for the melting of ice at 0°C is :

  • Option 1)

    10.52 cal / (mol K)

  • Option 2)

    21.04 cal / (mol K)

  • Option 3)

    5.260 cal / (mol K)

  • Option 4)

    0.526 cal / (mol K)

 
Engineering
51 Views   |  

In which of the following reactions, standard reaction entropy change (\DeltaS°) is Positive and standard Gibbs energy change (\DeltaG°) decreases sharply with increasing temperature?

  • Option 1)

    \text{C}\ \text{graphite}+\frac{1}{2}\text{O}_{2(\text{g})}\rightarrow \text{CO}_{(\text{g})}

  • Option 2)

    \text{CO}_{(\text{g})}+\frac{1}{2}\text{O}_{2(\text{g})}\rightarrow \text{CO}_{2(\text{g})}

  • Option 3)

    \text{Mg}_{(\text{s})}+\frac{1}{2}\text{O}_{2(\text{g})}\rightarrow \text{MgO}_{(\text{s})}

  • Option 4)

    \frac{1}{2}\text{Cgraphite}+\frac{1}{2}\text{O}_{2(\text{g})}\rightarrow\frac{1}{2} \text{CO}_{2(\text{g})}

 
Engineering
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Equal volumes of two monoatomic gases A and B, at same temperature and pressure are mixed. The ratio of specific heats (Cp/Cv) of the mixture will be:

  • Option 1)

    1.50

  • Option 2)

    3.3

  • Option 3)

    1.67

  • Option 4)

    0.83

 
Engineering
82 Views   |  

Which of the following is/are the hazardous pollutants present in automobile exhaust gases?

1) N_{2}

2) CO

3) CH_{4}

4) Oxides of nitrogen

 

  • Option 1)

    2 & 3

  • Option 2)

    1 & 2

  • Option 3)

    2 & 4

  • Option 4)

    1 & 3

 
As we learned @1825   Co and oxides of nitrogen gases are emitted as a result of the combustion of fuels. Option 1) 2 & 3 Option 2) 1 & 2 Option 3) 2 & 4 Option 4) 1 & 3
Engineering
100 Views   |  

Which one of the alkali metals, forms only, the normal oxide, M_{2}O on heating in air?

  • Option 1)

    Rb

  • Option 2)

    K

  • Option 3)

    Li

  • Option 4)

    Na

 

Li

 

Engineering
106 Views   |  

Which of the following oxides is not expected to react with sodium hydroxide?

  • Option 1)

    C_{a}O

  • Option 2)

    S_{i}O_{2}

  • Option 3)

    B_{e}O

  • Option 4)

    B_{2}O_{3}

 
As learnt Alkaline earth metals - Elements of Group 2 of the periodic table Be, Mg, Ca, Sr, Ba, Ra - wherein Their oxides are alkaline except Be    The oxides of alkaline earth metals are basic (except BeO) and basic oxides don't react with NaOH which also is basic. Option 1) This option is correct Option 2) This option is incorrect Option 3) This option is incorrect Option 4) This option...
Engineering
125 Views   |  

Structures of some common polymers are given. Which one is not correctly presented?

  • Option 1)

    Neoprene

  • Option 2)

    Terylene

  • Option 3)

    Nylon

  • Option 4)

    Teflon

 
As we learnt in  Neoprene - - Formed by free radical polymerization of chloroprene ( 2-chloro-1, 3-butadiene ). - Homopolymer - wherein - Superior resistance to vegetable and mineral oils. - Used in manufacturing conveyor belts, gaskets, hoses.   Neoprene is a polymer of chloroprene. structure Option 1) Correct Option 2) Incorrect Option 3) Incorrect Option 4) Incorrect
Engineering
100 Views   |  

The number of octahedral void (s) per atom present in a cubic close-packed structure is:

  • Option 1)

    1

  • Option 2)

    3

  • Option 3)

    2

  • Option 4)

    4

 
As learnt in Voids - Voids are empty spaces in a unit cell. They are of four types: triangular, tetrahedral, octahedral, cubic. -    We know that the no. of actohedral voids in a close packed structure = no. of atoms for a cubic close packed structure, no. of atoms = 1  octahedral voids = 1   Option 1) 1 this option is correct Option 2) 3 this option is incorrect Option 3) 2 this option is...
Engineering
174 Views   |  

The Number of Carbon atoms per unit cell of diamond unit cell is :

  • Option 1)

    8

  • Option 2)

    6

  • Option 3)

    1

  • Option 4)

    4

 
As we learnt in  Diamond unit all is FCC with 4 atoms additionally bonded tetrahedrally which have full contribution to the all.  So, no.of atoms                               Option 1) 8 this option is correct Option 2) 6 this option is incorrect Option 3) 1 this option is incorrect Option 4) 4 this option is incorrect
Engineering
339 Views   |  

Lithium metal crystallises in a body centered cubic crystal. If the length of the side of the unit cell of lithium is 351 pm.the atomic radius of the lithium will be:

  • Option 1)

    151.8 pm

  • Option 2)

    75.5 pm

  • Option 3)

    300.5 pm

  • Option 4)

    240.8 pm

 
As learnt in Relation between radius of constituent particle, R and edge length, a for body centered cubic unit cell - -    for a BCC lattice, we know that   Option 1) 151.8 pm this option is correct Option 2) 75.5 pm this option is incorrect Option 3) 300.5 pm this option is incorrect Option 4) 240.8 pm this option is incorrect
Engineering
102 Views   |  

In Castner-Kellner cell for production of sodium hydroxide:

  • Option 1)

    Brine is electrolyzed with Pt electrodes

  • Option 2)

    Brine is electrolyzed using graphite electrodes

  • Option 3)

    Molten sodium chloride is electrolyzed

  • Option 4)

    Sodium amalgam is formed at mercury cathode

 
As we learnt in Preparation of NaOH by castner-Kellner cell - Also known as mercury cathode process by electrolysis of aq.solution of brine cathode:   Anode: - wherein Cell comprises of three compartments Outer compartment:Brine solution is electrolysed Central compartment: 2% NaOH solution and     In the Castner Kellner cell,  At cathode,  At anode,  Sodium Amalgam is formed at...
Engineering
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Copper crystallises in a face-centered cubic lattice with a unit cell length of 361 pm.What is the radius of copper atom in pm?

  • Option 1)

    157

  • Option 2)

    181

  • Option 3)

    108

  • Option 4)

    128

 
For an FCC lattice, we know  Option 1) 157 this option is incorrect Option 2) 181 this option is incorrect Option 3) 108 this option is incorrect Option 4) 128 this option is correct
Engineering
147 Views   |  

A metal crystallizes with a face-centered cubic lattice. The edge length of the unit cell is 408 pm. The diameter of the metal atom is:

  • Option 1)

    288 pm

  • Option 2)

    408 pm

  • Option 3)

    144 pm

  • Option 4)

    204 pm

 
For an FCC, where r= radius of atom a= edge length Option 1) 288 pm This option is correct Option 2) 408 pm This option is incorrect Option 3) 144 pm This option is incorrect Option 4) 204 pm This option is incorrect
Engineering
120 Views   |  

What is the density of N_{2} gas at 227^{o}C and 5.00 atm pressure? (R=0.0821 atm K^{-1} mol^{-1})

  • Option 1)

    0.29 g/ml

  • Option 2)

    1.40 g/ml

  • Option 3)

    2.81 g/ml

  • Option 4)

    3.41 g/ml

 
  Ideal Gas Law - - wherein P - Pressure V - Volume n - No. of Moles R - Gas Constant T - Temperature     Ideal Gas Law in terms of density - - wherein where d - density of gas P - Pressure R - Gas Constant T - Temperature M - Molar Mass      from ideal gas equation  Pv=nRT or PM=RT = Option 1) 0.29 g/ml This option is incorrect  Option 2) 1.40 g/ml This option is incorrect  Option 3) 2.81...
Engineering
256 Views   |  

Which condition is not satisfied by an ideal solution?

  • Option 1)

    \Delta _{mix}H=0

  • Option 2)

    \Delta _{mix}V=0

  • Option 3)

    \Delta _{mix}S=0

  • Option 4)

    Obeyance to Raoult's Law

 
As learnt Condition of ideality - Interaction between A - A; B - B are similar to A - B Interactions. eg. Hexane + Heptone Benzene + Toluere - wherein       Conditions for ideality for a solution are: Also, an ideal solution always Raoult's Law Option 1) This option is incorrect Option 2) This option is incorrect Option 3) This option is correct Option 4) Obeyance to Raoult's Law This...
Engineering
110 Views   |  

The values of \Delta H \ and \ \Delta S for the reaction, C_{\left ( graphite \right )}+CO_{2}_{\left ( g \right )}\rightarrow 2CO_{\left ( g \right )}  are 170kJ and 170JK^{-1}, respectively. The reaction will be spontaneous at

  • Option 1)

    910K

  • Option 2)

    1110K

  • Option 3)

    510K

  • Option 4)

    710K

 
  Gibb's free energy (? G) -   - wherein Gibb's free energy enthalpy of reaction entropy temperature    For the reaction to be spontaneous given is -Ve only when which is possible only at ie. reaction will be spontaneous P= V=.03m3 P Option 1) 910K Incorrect Option Option 2) 1110K Correct Option Option 3) 510K Incorrect Option Option 4) 710K Incorrect Option
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