The number of gram molecules of chlorine in hydrogen chloride molecules is -
1
5
2
50
3
100
4
10
Official Solution
Correct Option: (3)
Number of gram molecules =
02
PYQ 2010
medium
chemistryID: kcet-201
The amount of heat evolved when of is mixed with of is _______
1
2
3
4
Official Solution
Correct Option: (2)
In neutralisation of 1 mole of by 1 mole HCl, heat evolved To neutralise mole of by
mole of
heat evolved will be
03
PYQ 2013
medium
chemistryID: kcet-201
4 g of a hydrated crystal of formula AxH O has 0.8 g of water. If the molar mass of the anhydrous crystal (A) is 144 g mol , x value is
1
4
2
1
3
2
4
3
Official Solution
Correct Option: (3)
Answer (c) 2
04
PYQ 2020
easy
chemistryID: kcet-202
The percentage of -character in the hybrid orbitals of nitrogen in and respectively are
1
33.3%, 50%, 25%
2
33.3%, 25%, 50%
3
50%, 33.3%, 25%
4
25%, 50%, 33.3%
Official Solution
Correct Option: (3)
In , the steric number of is two (two sigma bonds). Thus, it is sp hybridized. Hence, the percentage s-character is .
In , the steric number of is three (three sigma bonds). Thus, it is hybridized. Hence the percentage s-character is .
In , the steric number of is four (four sigma bonds). Thus, it is hybridized.
Hence, the percentage s-character is
05
PYQ 2026
medium
chemistryID: kcet-202
Match List - I with List – II and select the correct option (Based on mole concept):
Codes:
1
a – ii, b – iv, c – i, d – iii
2
a – iii, b – i, c – iv, d – ii
3
a – i, b – iv, c – ii, d – iii
4
a – ii, b – iii, c – i, d – iv
Official Solution
Correct Option: (1)
Step 1: Analyze each item in List-I and find its corresponding value in List-II. (a) 2 moles of ethene (C H ):
Molar mass of ethene = (2 12.01) + (4 1.01) 28 g/mol.
Mass of 2 moles of ethene = 2 mol 28 g/mol = 56 g.
This matches with (ii) 56 g. So, a ii. (b) Molar mass is equal to 66 g:
This statement is poorly phrased. It likely means "The mass of the sample is 66 g". Let's check List-II for an option with a mass of 66 g.
Consider (iv) 1.5 mole of CO :
Molar mass of CO = 12 + (2 16) = 44 g/mol.
Mass of 1.5 moles of CO = 1.5 mol 44 g/mol = 66 g.
This matches. So, b iv. (c) 1 g of H :
Molar mass of H = 2 g/mol.
Moles of H = mass / molar mass = 1 g / 2 g/mol = 0.5 moles.
Volume of 0.5 moles of any gas at STP = 0.5 mol 22.4 L/mol = 11.2 L.
This matches with (i) 11.2 L volume at STP. So, c i. (d) 2 moles of water vapours (H O):
Number of molecules in 2 moles = 2 mol Avogadro's number (N )
= 2 6.022 10 molecules = 12.044 10 molecules.
This matches with (iii) 12.04 10 molecules. So, d iii. Step 2: Compile the matches.
The correct matches are: a ii, b iv, c i, d iii. Step 3: Final Answer:
This combination corresponds to option (A).
