1.
How many significant figures are present in the number $0.00250$?
2.
Express $37^\circ\text{C}$ (normal human body temperature) in Fahrenheit
($^\circ\text{F}$).
3.
Write the SI unit for amount of substance and luminous intensity.
4.
Round off the number $34.216$ to three significant figures.
5.
Express the number $234,000$ in scientific notation to three significant figures.
6.
Calculate the result of $2.5 \times 1.25$ keeping significant figures in mind.
7.
Which of the following is temperature dependent: Mass, Volume, or Density?
8.
A student measures a mass of $2.00\text{ g}$ three times as $1.95\text{ g}$,
$1.93\text{ g}$, and $1.94\text{ g}$. Are these measurements accurate or precise?
9.
Which law of chemical combination states that a given compound always contains
exactly the same proportion of elements by weight?
10.
Carbon and oxygen combine to form $\text{CO}$ and $\text{CO}_2$. Which law is
illustrated by this observation?
11.
If $20\text{ mL}$ of hydrogen reacts with $10\text{ mL}$ of oxygen to yield water
vapor, what volume of water vapor is produced? (Assume constant T and P).
12.
State Avogadro's Law.
13.
Which postulate of Dalton's atomic theory is a direct result of the Law of
Conservation of Mass?
14.
Is air a mixture or a pure substance?
15.
A sample of $\text{CaCO}_3$ on heating decomposes to give $56\text{ g}$
$\text{CaO}$ and $44\text{ g}$ $\text{CO}_2$. How much starting $\text{CaCO}_3$ was taken?
16.
Define 1 Atomic Mass Unit (amu).
17.
Chlorine occurs in nature in two isotopic forms, with masses $35\text{ u}$ and
$37\text{ u}$ in the ratio of $3:1$. Calculate its average atomic mass.
18.
Calculate the molecular mass of sulfuric acid ($\text{H}_2\text{SO}_4$).
19.
Calculate the molecular mass of glucose ($\text{C}_6\text{H}_{12}\text{O}_6$).
20.
The vapour density of a gas is $22$. What is its molar mass?
21.
Using Dulong and Petit's Law, find the approximate atomic weight of a metal whose
specific heat is $0.16\text{ cal/g}^\circ\text{C}$.
22.
What is the mass of one single atom of Carbon-12 in grams?
23.
How many moles are present in $36\text{ g}$ of water?
24.
Calculate the number of molecules present in $0.5\text{ mole}$ of $\text{CO}_2$.
25.
What is the volume occupied by $1\text{ mole}$ of any ideal gas at STP?
26.
Calculate the mass of $0.1\text{ mole}$ of methane ($\text{CH}_4$).
27.
How many moles of gas are present in $11.2\text{ L}$ of $\text{N}_2$ at STP?
28.
Calculate the total number of atoms in $0.1\text{ mole}$ of a triatomic gas like
ozone ($\text{O}_3$).
29.
Which of the following contains the maximum number of molecules: $7\text{ g}$
$\text{N}_2$, $2\text{ g}$ $\text{H}_2$, or $16\text{ g}$ $\text{NO}_2$?
30.
What is the mass of $N_A$ ($6.022 \times 10^{23}$) atoms of Oxygen?
31.
Calculate the charge of $1\text{ mole}$ of electrons (1 Faraday).
32.
How many moles of electrons weigh one kilogram? (Mass of one electron = $9.1
\times 10^{-31}\text{ kg}$).
33.
What is the total number of ions present in $1\text{ mole}$ of $\text{NaCl}$?
34.
How many moles of Oxygen atoms are present in $2\text{ moles}$ of
$\text{H}_2\text{SO}_4$?
35.
Calculate the mass percentage of Carbon in $\text{CO}_2$.
36.
Calculate the mass percentage of water of crystallization in Blue Vitriol
($\text{CuSO}_4 \cdot 5\text{H}_2\text{O}$). [Atomic masses: Cu=63.5, S=32, O=16, H=1]
37.
What is the empirical formula of Benzene ($\text{C}_6\text{H}_6$)?
38.
A compound contains $50\%$ element A (atomic mass = $10$) and $50\%$ element B
(atomic mass = $20$). Find its empirical formula.
39.
The empirical formula of a compound is $\text{CH}_2\text{O}$ and its molar mass
is $180\text{ g/mol}$. Deduce its molecular formula.
40.
Find the percentage of Nitrogen in Urea ($\text{NH}_2\text{CONH}_2$).
41.
Balance the given equation: $\text{Fe}_2\text{O}_3 + \text{CO} \rightarrow
\text{Fe} + \text{CO}_2$.
42.
In the reaction $\text{N}_2 + 3\text{H}_2 \rightarrow 2\text{NH}_3$, identify the
limiting reagent if $1\text{ mole}$ of $\text{N}_2$ reacts with $2\text{ moles}$ of $\text{H}_2$.
43.
Calculate the mass of $\text{CO}_2$ produced by the complete thermal
decomposition of $10\text{ g}$ of $\text{CaCO}_3$.
44.
For the reaction $2\text{A} + \text{B} \rightarrow \text{A}_2\text{B}$, $50\text{
g}$ of A reacts with $50\text{ g}$ of B. ($M_A=10$, $M_B=20$). Which is the limiting reagent?
45.
If the theoretical yield of a reaction is $20\text{ g}$ and the actual yield is
$15\text{ g}$, what is the percentage yield?
46.
Calculate the Molarity of a solution containing $4\text{ g}$ of $\text{NaOH}$ in
$250\text{ mL}$ of solution.
47.
Calculate the Molality of a solution made by dissolving $20\text{ g}$ of
$\text{NaOH}$ in $100\text{ g}$ of water.
48.
What is the mole fraction of the solute if $1\text{ mole}$ of solute is dissolved
in $3\text{ moles}$ of solvent?
49.
Find the Normality of a $1\text{ M}$ $\text{H}_2\text{SO}_4$ solution.
50.
Express the concentration in parts per million (ppm) if $2\text{ g}$ of a solute
is dissolved in $1000\text{ kg}$ of solution.
1. 3
2. $98.6^\circ\text{F}$
3. mole, cd
4. $34.2$
5. $2.34 \times 10^5$
6. $3.1$
7. Volume & Density
8. Precise, not accurate
9. Definite Proportions
10. Multiple Proportions
11. $20\text{ mL}$
12. $V \propto n$
13. Atoms neither created/destroyed
14. Mixture
15. $100\text{ g}$
16. $1/12$ mass C-12
17. $35.5\text{ u}$
18. $98\text{ u}$
19. $180\text{ u}$
20. $44\text{ g/mol}$
21. $\approx 40$
22. $1.99 \times 10^{-23}\text{g}$
23. $2\text{ moles}$
24. $3.011 \times 10^{23}$
25. $22.4\text{ L}$
26. $1.6\text{ g}$
27. $0.5\text{ moles}$
28. $1.806 \times 10^{23}$
29. $2\text{g } \text{H}_2$ ($1\text{ mol}$)
30. $16\text{ g}$
31. $96485\text{ C}$
32. $1.82 \times 10^6$
33. $2 \times N_A$
34. $8\text{ moles}$
35. $27.27\%$
36. $36.07\%$
37. $\text{CH}$
38. $\text{A}_2\text{B}$
39. $\text{C}_6\text{H}_{12}\text{O}_6$
40. $46.6\%$
41. $\text{Fe}_2\text{O}_3 + 3\text{CO} \rightarrow
2\text{Fe} + 3\text{CO}_2$
42. $\text{H}_2$
43. $4.4\text{ g}$
44. Reagent A
45. $75\%$
46. $0.4\text{ M}$
47. $5\text{ m}$
48. $0.25$
49. $2\text{ N}$
50. $2\text{ ppm}$
