Some Basic Concepts of Chemistry Set-1

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

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:

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

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

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

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

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

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:

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?

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 $\text{Fe} = 56$):