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ChemistryPrinciples of Instrumental Analysis(a) Interpretation: The counting rate 9cpm is the background counting rate in the laboratory which was measured at the time period of 3 min and it is required that the value of standard relative deviation should be less than the 5% ( σ R c / R c < 0.05 ) . The total number of count is to be determined when the counting rate is 50cpm. Concept introduction: The formula for the standard deviation for the corrected counting rate is given as- σ R c = R x t x + R b t b ……. (1) Where, R x = counting rate for sample R b = counting rate for background t x = time required for counting rate for sample t b = time required for counting rate for background σ R c = standard deviation for the corrected counting rate Relative standard deviation is represented by the following formula- = σ R c R c …… (2) Also, R c = R x − R bStart your trial now! First week only $4.99!*arrow_forward*

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7th Edition

Douglas A. Skoog + 2 others

Publisher: Cengage Learning

ISBN: 9781305577213

Chapter 32, Problem 32.8QAP

Interpretation Introduction

**(a)**

**Interpretation:**

The counting rate 9cpm is the background counting rate in the laboratory which was measured at the time period of 3 min and it is required that the value of standard relative deviation should be less than the 5%

**Concept introduction:**

The formula for the standard deviation for the corrected counting rate is given as-

Where,

Relative standard deviation is represented by the following formula-

Also,

Interpretation Introduction

**(b)**

**Interpretation:**

The counting rate 9cpm is the background counting rate in the laboratory which was measured at the time period of 3 min and it is required that the value of standard relative deviation should be less than the 5%

**Concept introduction:**

The formula for the standard deviation for the corrected counting rate is given as-

Where,

Relative standard deviation is represented by the following formula-

Also,