Some Basic Concepts of Chemistry

Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation: N2 (g) + H2(g)→ 2NH3 (g) (i) Calculate the mass of NH_{ 3 } ​ produced if 2 \; \times \;10^{ 3 } g N_2 reacts with 1 \; \times \;10^{ 3 } g of H_{2}? (ii) Will any of the two reactants remain unreacted? (iii) If yes, which one and what would be its mass.

(i) Balance the given equation: $N_{ 2 }\;(g)  \; + \; 3H_{ 2 } \;(g) \; \rightarrow \; 2NH_{ 3 }\;(g) $   Thus, 1 mole (28 g) of N2 reacts with 3 mole (6 g) of H2 to give 2 mole (34 g)...

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Calcium carbonate reacts with aqueous HCl to give CaCl2 and CO2 according to the reaction, CaCO3 (s) + 2 HCl (aq) → CaCl2(aq) + CO2 (g) + H2O(l) What mass of CaCO3 is required to react completely with 25 mL of 0.75 M HCl?

0.75 M of HCl ≡ 0.75 mol of HCl are present in 1 L of water ≡ $[(0.75 mol)\times(36.5 g mol–1 )]$ HCl is present in 1 L of water ≡ 27.375 g of HCl is present in 1 L of water Thus, 1000 mL of...

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Chlorine is prepared in the laboratory by treating manganese dioxide (MnO2) with aqueous hydrochloric acid according to the reaction: 4 HCl (aq) + MnO2(s) → 2H2O (l) + MnCl2(aq) + Cl2 (g) How many grams of HCl react with 5.0 g of manganese dioxide?

1 mol of $MnO_{2}$​ = 55 + 2 × 16 = 87 g 4 mol of HCl = 4 × 36.5 = 146 g 1 mol of $MnO_{2}$​ reacts with 4 mol of HCl 5 g of $MnO_{ 2 }$will react with: =$ \frac{146 \; g}{87 \; g} \; \times \; 5...

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In a reaction A + B2 → AB2 Identify the limiting reagent, if any, in the following reaction mixtures. (i) 300 atoms of A + 200 molecules of B (ii) 2 mol A + 3 mol B (iii) 100 atoms of A + 100 molecules of B (iv) 5 mol A + 2.5 mol B (v) 2.5 mol A + 5 mol B

Reagent limitation: It establishes the magnitude of a reaction. It is the first to be consumed in a reaction, causing the process to come to a halt and limiting the number of products produced. (i)...

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The following data are obtained when dinitrogen and dioxygen react together to form different compounds:;(a) Which law of chemical combination is obeyed by the above experimental data? Give its statement. (b) Fill in the blanks in the following conversions: (i) 1 km = …………………. mm = …………………. pm (ii) 1 mg = …………………. kg = …………………. ng (iii) 1 mL = …………………. L = …………………. dm3

(a) If the mass of N2 is set at 28 g, the mass of O2 that will combine with it is 32 grammes, 64 grammes, 32 grammes, and 80 grammes. O2 has a mass-to-number ratio of 1: 2: 1: 5. As a result, the...

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A sample of drinking water was found to be severely contaminated with chloroform, CHCl3, supposed to be carcinogenic in nature. The level of contamination was 15 ppm (by mass). (i) Express this in per cent by mass. (ii) Determine the molality of chloroform in the water sample.

(a) $1 ppm = 1 part out of 1 million parts.$ Mass percent of 15 ppm chloroform in H2O= $\frac{15}{{{10}^{6}}}\times 100$ $\approx 1.5 \times{10}^{-3}%$ $ (b)$100 grams of the sample is having 1.5 ×...

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A box contains some identical red coloured balls, labelled as A, each weighing 2 grams. Another box contains identical blue coloured balls, labelled as B, each weighing 5 grams. Consider the combinations AB, AB2, A2B and A2B3 and show that the law of multiple proportions is applicable.

AB ab2 A,B A2B3 Mass of A (in g) 2 2 4 415 Mass of B (in g) 5 10 5   According to the law of multiple proportions, Masses of B combines with a constant mass of A are 10g, 20g, 5g, 15g Simple...

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Assertion (A): Significant figures for 0.200 is 3 whereas for 200 it is 1. Reason (R): Zero at the end or right of a number are significantly provided they are not on the right side of the decimal point. (i) Both A and R are true and R is the correct explanation of A. (ii) Both A and R are true but R is not a correct explanation of A. (iii) A is true but R is false. (iv) Both A and R are false.

Correct Answer: (iii) A is true but R is false Explanation: Zero at the end of a number without the decimal point is not significantly based on the rate of accuracy.

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The reactant which is entirely consumed in the reaction is known as limiting reagent. In the reaction 2A + 4B → 3C + 4D, when 5 moles of A react with 6 moles of B, then (i) which is the limiting reagent? (ii) calculate the amount of C formed?

(i) The reactant B is the the limiting reagent. (ii) Calculation: Let us consider that the reactant B got completely consumed as it is the limiting reagent. 4 mol of B gives 3 mol of C 6 mol of B...

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Two students performed the same experiment separately and each one of them recorded two readings of mass which are given below. The correct reading of mass is 3.0 g. Based on given data, mark the correct option out of the following statements. Student Readings

(i) (ii) A 3.01 2.99 B 3.05 2.95 (i) Results of both the students are neither accurate nor precise. (ii) Results of student A are both precise and accurate. (iii) Results of student B are neither...

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