Important question of chemistry

Number of Isotopes which have been produced through
artificial disintegration are:
A. 280
B. 40
C. 300
D. none of these
2. Number of atoms in 10g of hydrogen are equal to
A. 24g of Mg
B. 60g of C
C. 230g of Na
D. 238g of U
3. According to the Greek philosophers matter consists of
smaller particles known as
A. atoms
B. molecules
C. ions
D. basic units
4. In mass spectrometer the applied magnetic field move the

ions in a ______ path
A. linear
B. parabolic
C. elliptical
D. circular
5. Which of the following will form the anion with largest
ionic radius to get the noble gas electronic configuration?
A. Na
B. P
C. S
D. Cl
6. In non- stoichiometric reactions, amount of product
depends upon
A. limiting reactant
B. excess reactant
C. both a and b
D. none of these
7. Calcium has ____ isotopes
A. 5
B. 6
C. 1
D. 3
8. In combustion analysis the method of difference is used to
find out the mass of which of the following
A. CO2
B. H2O
C. both a and b
D. O
9. Ti identify the limiting reactant ____ steps are used
A. 2
B. 4
C. 5
D. 3
10. Actual yield is _____ than the theoretical yield
A. greater
B. less
C. equal
D. can be any a, b and c
11. A ring has 18 grams of diamond. What is the number of
diamond atoms in it
A. 6.022 x 10^23
B. 1.5 x 6.022 x 10^23
C. 2 x 6.022 x 10^23
D. 3 x 6.022 x 10^23
12. Equal volumes of CO and N2 are taken in identical
conditions. The correct relationship between the masses of two gasses
is:
A. CO < N2
B. CO = N2
C. CO > N2
D. All are possible
13. In the following reaction, how many liters of SO2 at STP
will result from complete burning of sulfur in 8 liters of oxygen?
S(s) + O2(g) --> SO2(g)
A. 4
B. 1
C. 16
D. 8
14. How many grams of hydrogen gas can be produced from the
following reaction if 65grams of zinc and 65grams of HCl are present in
the reaction?
Zn(s) + 2HCl(aq) --> ZnCl2(aq) + H2(g)
A. 1
B. 1.8
C. 3.6
D. 7
15. What mass of CaCO3 is needed to produce 11.2 liters of CO2
when the calcium carbonate is reacted with an excess amount of
hydrochloric acid?
A. 25g
B. 44g
C. 100g
D. 50g
16. How many moles of electrons are required to reduce 2.93
grams of nickel ions from melted NiCl2?
A. 0.1
B. 1.5
C. 2.0
D. 1.0
17. If 49 grams of H2SO4 react with 80 grams of NaOH, how much
reactant will be left over after the reaction is complete?
A. 24.5 g of H2SO4
B. 20g of NaOH
C. 60g of NaOH
D. 40g of NaOH
18. From 2 moles of KClO3 how many liters of O2 can be produced
at STP by decomposition of all of the KClO3?
A. 67.2
B. 11.2
C. 33.6
D. 44.9
19. What is the approximate percentage of oxygen in the formula
mass of Ca(NO3)2?
A. 28
B. 42
C. 58
D. 84
20. Which formulas could represent the empirical formula and
the molecular formula of a given compound?
A. CH2O and C4H6O4
B. CH2 and C3H6
C. CO and CO2
D. CH4 and C5H12
21. Four grams of hydrogen gas at STP contains:
A. 6.02 x 10^23 atoms
B. 12.04 x 10^23 atoms
C. 1.2 x 10^23 molecules
D. 12.04 x 10^23 molecules
22. Analysis of a gas gave C=85.7% and H=14.3%. If the formula
mass of the gas is 42 amu, what are the empirical formula and the true
formula?
A. CH2 and C3H6
B. CH and C4H4
C. C2H2 and C3H6
D. CH3 and C3H9
23. What is the mass in grams of one mole of KAl(SO4)2.12H2O ?
A. 132
B. 474
C. 394
D. 180
24. Efficiency of a chemical reaction can be checked by
calculating:
A. amount of limiting reactant
B. amount of reactant in excess
C. amount of reactant unused
D. amount of product formed
25. When 60cm^3 of both H2 and O2 are made to react to give
water the volume of reactants left over will be?
A. 30cm^3
B. 60cm^3
C. 45cm^3
D. 20cm^3
26. Which of the following has the highest percentage of
nitrogen?
A. (NH4)3PO4
B. (NH4)2SO4
C. (NH4)2HPO4
D. NH4H2PO4
27. How many gram atoms of oxygen are present in 0.16 moles of
water?
A. 16g atoms
B. 8g atoms
C. 0.8g atoms
D. 0.16g atoms
28. The volume occupied by 0.4 moles of CO2 at STP is?
A. 7.9
B. 2.9
C. 0.02
D. 8.9
29. The number of moles of CO2 which contain 16g of oxygen is?
A. 0.25
B. 0.5
C. 0.75
D. 1.00
30. In the reaction
4Al + 3O2 --> 2Al2O3
If amount of Al is 1/4 moles then how many moles of O2 are required?
A. 3/4
B. 4/3
C. 4/16
D. 3/16