1 ) What is concentration of nitrate ions , if equal volume 0.1 M AgNO3 and 0.1 M of NaCl are mixed together ?
A ) 0.05 M , B
) 1.0 M ,
C ) 1.5 M , D
) None of these ,
Correct
Answer : - A ) 0.05 M ,
Solution
: -
So AgNO3 has two ions = 0.1 / 2 = 0.05 M ,
Answer .
So , 0.05 mole of
nitrate ions are produced .
2 )
The volume in liters of CO2 liberated at STP when 10 gram of 90 % pure
limestone is heated completely is : -
A ) 1 , B
) 2 ,
C ) 4 , D
) None of these ,
Correct
Answer : - B ) 2 ,
Solution
: -
CaCO3 ------> CaO + CO2 ,
limestone : -
CaCO3 ,
So molecular mass of CaCO3 = 100 g / mole .
90 % of 10 g of limestone = 10 x
90 / 100 = 9 gram .
So , moles of limestone = mass / molecular mass = 9 / 100
= 0.09 mol .
so ,
1 M of CaCO3 = 1 M of CO2 .
0.09 M of CaCO3 = 0.09 M of CO2 .
So now calculate volume of CO2 at STP : -
volume
= moles x STP = 0.09 x 22.4 = 2 ,
Answer .
3 )
The favorable conditions for ammonia production from Haber process are : -
A ) High pressure and low temperature ,
B ) Low pressure and high temperature ,
C ) Not effected by pressure and temperature ,
D ) None of these ,
Correct
Answer : - A ) High pressure and low
temperature ,
Because
by high pressure , no. of moles will get decrease and by low temperature , the reaction will
get exothermic .
4 )
Order of joule , calorie and erg : -
1
calorie > 1 Joule > 1 erg .
Because ;
1 joule = 10^7 erg .
1 calorie = 4.18 joule .
