Some Basic Concepts of Chemistry Set-1

Test your knowledge on Some Basic Concepts of Chemistry from Chemistry, Class 11.

Minutes

Questions

1 / -0

Marking Scheme

Don't have an account? Sign up for free to save your progress and track your history.

Questions in this Quiz

Q1: What will be the molarity of a solution, which contains $5.85\text{g of } \text{NaCl}(\text{s}) \text{ per } 500\text{mL}$?

$4\text{ mol L}^{-1}$
$20\text{ mol L}^{-1}$
$0.2\text{ mol L}^{-1}$
$2\text{ mol L}^{-1}$

Q2: Zinc sulphate contains $22.65\%$ zinc and $43.9\%$ water of crystallisation. If the law of constant proportions is true, then the weight of zinc required to produce $20\text{g}$ of the zinc sulphate crystals will be:

$45.3\text{g}$.
$4.53\text{g}$.
$0.453\text{g}$.
$453\text{g}$.

Q3: What will be the molality of the solution made by dissolving $10\text{g of } \text{NaOH} \text{ in } 100\text{g of water}$?

$2.5\text{m}$.
$5\text{m}$.
$10\text{m}$.
$1.25\text{m}$.

Q4: Which of the following statements is/ are incorrect?

The weight of a substance can be determined very accurately by using an analytical balance.
Volume is denoted in $\text{dm}$ units.
Density of a substance is its amount present per unit volume.
Candela is the luminous intensity, that emits monochromatic radiation of frequency, $540 \times 10^{12}\text{ Hz}$.

Q5: One mole of oxygen gas at $\text{STP}$ is equal to:

$6.022 \times 10^{23}$ molecules of oxygen.
$6.022 \times 10^{23}$ atoms of oxygen.
$16\text{g}$ of oxygen.
$32\text{g}$ of oxygen.

Q6: The result reported in the following multiplication of significant figures, $2.5 \times 1.25 = 3.125$ should be:

$3.125$
$3.1$
$3.12$
$3.10$

Q7: How many number of aluminium ions are present in $0.051\text{g of aluminium oxide } (\text{Al}_2\text{O}_3)$?

$6.023 \times 10^{23} \text{ ions}$.
$3 \text{ ions}$.
$6.023 \times 10^{20} \text{ ions}$.
$9 \text{ ions}$.

Q8: The solution of A and B are $0.1$ and $0.2$ molar in a substance. If $100\text{mL of ‘A’}$ are mixed with $25\text{mL of B}$ and there is no change in volume, then the final molarity of solution is:

$0.15\text{M}$
$0.18\text{M}$
$0.12\text{M}$
$0.30\text{M}$

Q9: One of the statements of Dalton’s atomic theory is given below: “Compounds are formed when atoms of different elements combine in a fixed ratio.” Which of the following laws is not related to this statement?

Law of conservation of mass.
Law of definite proportions.
Law of multiple proportions.
Avogadro law.

Q10: The weight of iron which will be converted into its oxide $(\text{Fe}_3\text{O}_4)$ by the action of $18\text{g of steam}$ on it will be (Atomic weight of $\text{Fe} = 56$):

$168\text{g}$.
$84\text{g}$.
$42\text{g}$.
$21\text{g}$.

Q11: How many number of molecules and atoms respectively are present in $2.8\text{L of a diatomic gas at STP}$?

$6.023 \times 10^{23} , 7.5 \times 10^{23}$
$6.023 \times 10^{23} , 15 \times 10^{22}$
$7.5 \times 10^{22} , 15 \times 10^{22}$
$15 \times 10^{22} , 7.5 \times 10^{23}$

Q12: A gas is found to have the formula $(\text{CO})_x$. Its vapour density is $70$. The value of $x$ will be:

Q13: The mass of one mole of a chloride formed by metal ‘$\text{X}$’ is $111.0\text{g}$. Which one could be the formula of the chloride?

$\text{XCl}$
$\text{XCl}_2$
$\text{XCl}_3$
$\text{XCl}_4$

Q14: Which law states that if two elements can combine to form more than one compound, the masses of one element that combine with a fixed mass of other element, are in the ratio of small whole numbers?

Avogadro’s law.
Law of definite composition.
Law of multiple proportions.
Gay Lussac’s law of gaseous volumes.

Q15: Which set of figures will be obtained after rounding up to three significant figures $1.386, 4.334, 2.808$?

$1.39, 4.34, 2.809$
$1.39, 4.33, 2.81$
$1.38, 4.34, 2.800$
$1.39, 4.34, 2.80$

Q16: Total mass of the reactant is equal to the total mass of the product. This statement is related to which law?

Law of Mass Action
Law of Conservation of Mass
Law of Multiple Proportion
Avogadro's Law

Q17: The number $6.022 \times 10^{23}$ entities (atoms/molecules) in one mole is known as:

Planck's Constant
Avogadro's Number
Equilibrium Constant
Exponential Constant

Q18: Which of the following correctly represents $180\text{ gram of water}$?

$5\text{ mol of water}$
$1\text{ mol of water}$
$6.023 \times 10^{23}$ molecules of water
$6.023 \times 10^{24}$ molecules of water

Q19: A solution contains $6.02 \times 10^{20}$ molecules of Urea in $100\text{ mL of its solution}$. The concentration (Molarity) of the solution is:

$0.02\text{ M}$
$0.2\text{ M}$
$0.01\text{ M}$
$0.1\text{ M}$

Q20: An organic compound has an empirical formula $\text{CH}_2\text{O}$. Its vapour density is $45$. The molecular formula is:

$\text{CH}_2\text{O}$
$\text{C}_2\text{H}_5\text{O}$
$\text{C}_6\text{H}_{12}\text{O}_6$
$\text{C}_3\text{H}_6\text{O}_3$

Q21: $2\text{g of substance A}$ (solute) is mixed with $18\text{g of substance B}$ (solvent). Calculate the mass percentage of the solute (A).

$8\%$
$9\%$
$10\%$
$20\%$

Q22: What is the mole fraction of the solute in one molal aqueous solution?

$0.0177$
$0.177$
$1.77$
$0.77$

Q23: What is the molarity of pure water? ($\text{Density } 1\text{ g/mL}$)

$18\text{ M}$
$100\text{ M}$
$55.6\text{ M}$
$50\text{ M}$

Q24: $750\text{ mL of } 0.5\text{ M HCl}$ is mixed with $250\text{ mL of } 2\text{ M HCl}$. What is the final molarity of the solution?

$0.875\text{ M}$
$1.0\text{ M}$
$1.5\text{ M}$
$2.5\text{ M}$

Q25: How much copper can be obtained from $100\text{ gram of Copper Sulphate } (\text{CuSO}_4)$? (Atomic weight $\text{Cu} = 63.5$)

$45.79\text{ g}$
$35.8\text{ g}$
$39.8\text{ g}$
$41.5\text{ g}$

Q26: What will be the mass of one $\text{Carbon-12}$ atom in grams?

$1.9927 \times 10^{-24}\text{ g}$
$1.9927 \times 10^{-23}\text{ g}$
$12\text{ g}$
$2.0 \times 10^{-23}\text{ g}$

Q27: Which of the following reaction is NOT correct according to the Law of Conservation of Mass?

$2\text{Mg} + \text{O}_2 \to 2\text{MgO}$
$\text{C}_3\text{H}_8 + \text{O}_2 \to \text{CO}_2 + \text{H}_2\text{O}$
$4\text{P} + 5\text{O}_2 \to \text{P}_4\text{O}_{10}$
$\text{H}_2 + \text{Cl}_2 \to 2\text{HCl}$

Q28: Which of the following term is unitless?

Molality
Molarity
Mole fraction
Percentage by mass

Q29: Choose the incorrect match regarding SI units:

Amount of substance: $\text{mole}$
Luminous Intensity: $\text{candela}$
Unit of Time: $\text{minute}$
Unit of Length: $\text{meter}$

Q30: Calculate the Molecular Weight if the Vapour Density is $22$.

$32$
$36$
$44$
$64$