Given the characteristics listed below for a "typical" river, determine the following parameters related to drinking water quality. The water temperature is 25°C. What is the total hardness: Consider only two major species that contribute the most to total hardness. Choose your answer from the following. Species Ca²+ Mg2+ Na+ Fe³+ Concentration (mg/L) 15 4.1 6.3 0.67 (a) 55 meq/L (b) 1.1 meq/L (c) 1.09 mg/L as CaCO3 (d) 50 mg/L as CaCO3 Molecular weight 40 24 23 55.8 Species HCO3 CO3²- SO4²- SiO₂ Concentration (mg/L) 58.4 0.0085 11.2 13.1 Molecular weight 61 60 96 60.08

Structural Analysis
6th Edition
ISBN:9781337630931
Author:KASSIMALI, Aslam.
Publisher:KASSIMALI, Aslam.
Chapter2: Loads On Structures
Section: Chapter Questions
Problem 1P
icon
Related questions
Question

homework

**Transcription for Educational Website:**

---

**Water Quality Analysis of a "Typical" River**

Given the characteristics listed below for a “typical” river, determine the following parameters related to drinking water quality. The water temperature is 25°C.

**What is the total hardness?** Consider only two major species that contribute the most to total hardness. Choose your answer from the following:

| **Species** | **Concentration (mg/L)** | **Molecular weight** |
|-------------|--------------------------|----------------------|
| Ca²⁺        | 15                       | 40                   |
| Mg²⁺        | 4.1                      | 24                   |
| Na⁺         | 6.3                      | 23                   |
| Fe³⁺        | 0.67                     | 55.8                 |

| **Species** | **Concentration (mg/L)** | **Molecular weight** |
|-------------|--------------------------|----------------------|
| HCO₃⁻       | 58.4                     | 61                   |
| CO₃²⁻       | 0.0085                   | 60                   |
| SO₄²⁻       | 11.2                     | 96                   |
| SiO₂        | 13.1                     | 60.08                |

**Possible Answers:**

(a) 55 meq/L  
(b) 1.1 meq/L  
(c) 1.09 mg/L as CaCO₃  
(d) 50 mg/L as CaCO₃  

---

**Explanation:**

The table above provides the concentration and molecular weight of various species found in river water that contribute to its hardness. The task is to calculate total hardness using only the two major species, which typically are calcium (Ca²⁺) and magnesium (Mg²⁺), as they are the primary contributors to water hardness.

Hardness is typically expressed in terms of the equivalent amount of calcium carbonate (CaCO₃).

The tables list both cationic species (such as Ca²⁺ and Mg²⁺) and anionic species (such as HCO₃⁻ and SO₄²⁻). However, only cationic species are used in determining total hardness in water.
Transcribed Image Text:**Transcription for Educational Website:** --- **Water Quality Analysis of a "Typical" River** Given the characteristics listed below for a “typical” river, determine the following parameters related to drinking water quality. The water temperature is 25°C. **What is the total hardness?** Consider only two major species that contribute the most to total hardness. Choose your answer from the following: | **Species** | **Concentration (mg/L)** | **Molecular weight** | |-------------|--------------------------|----------------------| | Ca²⁺ | 15 | 40 | | Mg²⁺ | 4.1 | 24 | | Na⁺ | 6.3 | 23 | | Fe³⁺ | 0.67 | 55.8 | | **Species** | **Concentration (mg/L)** | **Molecular weight** | |-------------|--------------------------|----------------------| | HCO₃⁻ | 58.4 | 61 | | CO₃²⁻ | 0.0085 | 60 | | SO₄²⁻ | 11.2 | 96 | | SiO₂ | 13.1 | 60.08 | **Possible Answers:** (a) 55 meq/L (b) 1.1 meq/L (c) 1.09 mg/L as CaCO₃ (d) 50 mg/L as CaCO₃ --- **Explanation:** The table above provides the concentration and molecular weight of various species found in river water that contribute to its hardness. The task is to calculate total hardness using only the two major species, which typically are calcium (Ca²⁺) and magnesium (Mg²⁺), as they are the primary contributors to water hardness. Hardness is typically expressed in terms of the equivalent amount of calcium carbonate (CaCO₃). The tables list both cationic species (such as Ca²⁺ and Mg²⁺) and anionic species (such as HCO₃⁻ and SO₄²⁻). However, only cationic species are used in determining total hardness in water.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 3 steps with 5 images

Blurred answer
Knowledge Booster
Reactions with Materials
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.
Recommended textbooks for you
Structural Analysis
Structural Analysis
Civil Engineering
ISBN:
9781337630931
Author:
KASSIMALI, Aslam.
Publisher:
Cengage,
Structural Analysis (10th Edition)
Structural Analysis (10th Edition)
Civil Engineering
ISBN:
9780134610672
Author:
Russell C. Hibbeler
Publisher:
PEARSON
Principles of Foundation Engineering (MindTap Cou…
Principles of Foundation Engineering (MindTap Cou…
Civil Engineering
ISBN:
9781337705028
Author:
Braja M. Das, Nagaratnam Sivakugan
Publisher:
Cengage Learning
Fundamentals of Structural Analysis
Fundamentals of Structural Analysis
Civil Engineering
ISBN:
9780073398006
Author:
Kenneth M. Leet Emeritus, Chia-Ming Uang, Joel Lanning
Publisher:
McGraw-Hill Education
Sustainable Energy
Sustainable Energy
Civil Engineering
ISBN:
9781337551663
Author:
DUNLAP, Richard A.
Publisher:
Cengage,
Traffic and Highway Engineering
Traffic and Highway Engineering
Civil Engineering
ISBN:
9781305156241
Author:
Garber, Nicholas J.
Publisher:
Cengage Learning