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ChemistryMediumMCQ2016 · 10 Apr Online

Q48.Gold numbers of some colloids are Gelatin: 0. 005 −0. 01, Gum Arabic: 0. 15 −0. 25, Oleate: 0. 04 −1. 0 , Starch: 15 −25 . Which among the following is a better protective colloid? (1) Gelatin (2) Starch (3) Oleate (4) Gum Arabic

What This Question Tests

This question tests the definition and interpretation of the gold number, where a lower gold number signifies a greater protective power of a colloid.

Concepts Tested

Gold numberProtective action of colloidsLyophilic colloids

📚 NCERT Sections This Tests

3.10In A Reaction Between A And B, The Initial Rate Of Reaction (R0) Was Measured

Chemistry Class 11 · Chapter 3

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3.10 In a reaction between A and B, the initial rate of reaction (r0) was measured for different initial concentrations of A and B as given below: A/ mol L–1 0.20 0.20 0.40 B/ mol L–1 0.30 0.10 0.05 r0/mol L–1s–1 5.07 × 10–5 5.07 × 10–5 1.43 × 10–4 What is the order of the reaction with respect to A and B? 3.11 The following results have been obtained during the kinetic studies of the reaction: 2A + B ® C + D Experiment [A]/mol L–1 [B]/mol L–1 Initial rate of formation of D/mol L–1 min–1 I 0.1 0.1 6.0 × 10–3 II 0.3 0.2 7.2 × 10–2 III 0.3 0.4 2.88 × 10–1 IV 0.4 0.1 2.40 × 10–2 Determine the rate law and the rate constant for the reaction. 3.12 The reaction between A and B is first order with respect to A and zero order with respect to B. Fill in the blanks in the following table: Experiment [A]/ mol L–1 [B]/ mol L–1 Initial rate/ mol L–1 min–1 I 0.1 0.1 2.0 × 10–2 II – 0.2 4.0 × 10–2 III 0.4 0.4 – IV – 0.2 2.0 × 10–2 3.13 Calculate the half-life of a first order reaction from their rate constants given below: (i) 200 s–1 (ii) 2 min–1 (iii) 4 years–1 3.14 The half-life for radioactive decay of 14C is 5730 years. An archaeological artifact containing wood had only 80% of the 14C found in a living tree. Estimate the age of the sample. 3.15 The experimental data for decomposition of N2O5 [2N2O5 ® 4NO2 + O2] in gas phase at 318K are given below: t/s 0 400 800 1200 1600 2000 2400 2800 3200 102 × [N2O5]/ 1.63 1.36 1.14 0.93 0.78 0.64 0.53 0.43 0.35 mol L–1 (i) Plot [N2O5] against t. (ii) Find the half-life period for the reaction. (iii) Draw a graph between log[N2O5] and t. (iv) What is the rate law ? Chemistry 86 Reprint 2025-26 (v) Calculate the rate constant. (vi) Calculate the half-life period from k and compare it with (ii).

1.1Define The Term Solution. How Many Types Of Solutions Are Formed? Write Briefly

Chemistry Class 11 · Chapter 1

72% match

1.1 Define the term solution. How many types of solutions are formed? Write briefly about each type with an example.

1.23Suggest The Most Important Type Of Intermolecular Attractive Interaction In

Chemistry Class 11 · Chapter 1

72% match

1.23 Suggest the most important type of intermolecular attractive interaction in the following pairs. (i) n-hexane and n-octane (ii) I2 and CCl4 (iii) NaClO4 and water (iv) methanol and acetone (v) acetonitrile (CH3CN) and acetone (C3H6O). 1.24 Based on solute-solvent interactions, arrange the following in order of increasing solubility in n-octane and explain. Cyclohexane, KCl, CH3OH, CH3CN.

📋 Question Details

Chapter
Surface Chemistry
Topic
Protective colloids and gold number
Year
2016
Shift
10 Apr Online
Q Number
Q48
Type
MCQ
NCERT Ref
Class 12 Chemistry Ch 5: Surface Chemistry
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