CBSE
An element, X has the following isotopic composition;
200X: 90%
199X : 8.0%
202X ; 2.0 %
The weighted average atomic mass of the naturally -occurring element X is closet to:
200 amu
201 amu
202 amu
202 amu
The number average molar mass and mass average molar mass of a polymer are respectively 30,000 and 40,000. The
polydispersity index (PDI) of the polymer is
-1
0
> 1
< 1
The osmotic pressure of blood is 8.21 atm at 37C. How much glucose would be used for an injection that is at the same osmotic pressure as blood?
22.17 gL-1
58.14 gL-1
61.26 gL-1
75.43 gL-1
11.2 L of gas at STP Weight 14g. The gas would be
H2
CO
B2H6
All of these
For preparing 3.00 L of 1M NaOH by mixing portions of two stock solutions (A and B) of 2.50 M NaOH and 0.40 M NaOH respectively. Find out the amount of B stock solution (in L) added.
8.57 L
2.14 L
1.28 L
7.51 L
A solution made by dissolving 40 g NaOH in 1000 g of H2O is
1 molar
1 normal
1 molal
None of these
What would be the heat released when an aqueous solution containing 0.5 mole of HNO3 is mixed with 0.3 mole of OH-? (enthalpy of neutralisation is- 57.1 kJ)
28.5 kJ
17.1 kJ
45.7 kJ
1.7 kJ
In order to prepare one litre 1N solution of KMnO4, how many grams of KMnO4 are required, if the solution to be used in acid medium for oxidation?
128g
41.75 g
31.60 g
62.34 g
0.001 mole of [Co(NH3)5(NO3) (SO4)] was passed through a cation exchanger and the acid coming out of it required 20mL of 0.1 M NaOH for neutralisation. Thus, the complex is
[Co(NH3)5(NO3)] SO4
[Co(NH3)5(SO4)]NO3
[Co(NH3)5] NO3.SO4
None of the above
Work is being performed, when a weight lifter lifts a base ball off a weight rack. This is due to
magnetic attraction
gravity
electrostatic repulsion
mechanical force