Question

Write a program that computes the molecular weight of a carbohydrate (in grams per mole) based on the number of hydrogen, carbon, and oxygen atoms in the molecule. The program should prompt the user to enter the number of hydrogen atoms, the number of carbon atoms, and the number of oxygen atoms. The program then prints the total combined molecular weight of all the atoms based on these individual atom weights: Atom Weight \\[ \begin{array}{cc} & \text { (grams / mole) } \\ \hline \mathrm{H} & 1.00794 \\ \mathrm{C} & 12.0107 \\ \mathrm{O} & 15.9994 \end{array} \\] For example, the molecular weight of water \(\left(H_{2} O\right)\) is: \(2(1.00794)+\) \\[ 15.9994=18.01528. \\]

Short answer

Write a program to input atom counts, calculate, and output the molecular weight using provided atomic weights.

Step-by-step solution

Understanding the Problem

The task is to write a program that determines the molecular weight of a carbohydrate based on the count of hydrogen, carbon, and oxygen atoms supplied by the user. The program will use fixed molecular weights for each type of atom to calculate the overall molecular weight.

Define Molecular Weights

The problem provides specific atomic weights in grams per mole: - Hydrogen (H): 1.00794 g/mol - Carbon (C): 12.0107 g/mol - Oxygen (O): 15.9994 g/mol

Gather User Input

The program should prompt the user to input the number of hydrogen, carbon, and oxygen atoms. Store these inputs as integer or float variables, depending on whether fractional atoms are allowed (usually integers in chemistry).

Setup the Molecular Weight Calculation

Use the formula:\[\text{Molecular Weight} = (\text{H atoms} \times 1.00794) + (\text{C atoms} \times 12.0107) + (\text{O atoms} \times 15.9994)\]This formula calculates the total molecular weight based on the number of each type of atom.

Implement the Program Logic

Write the logic in a programming language of your choice (e.g., Python): ```python # Prompt for user input H_atoms = float(input("Enter the number of hydrogen atoms: ")) C_atoms = float(input("Enter the number of carbon atoms: ")) O_atoms = float(input("Enter the number of oxygen atoms: ")) # Calculate molecular weight molecular_weight = (H_atoms * 1.00794) + (C_atoms * 12.0107) + (O_atoms * 15.9994) # Print result print(f"The molecular weight is: {molecular_weight:.5f} grams/mole") ```

Program Testing and Verification

Test the program with known compounds to ensure accuracy. For instance, with water (H₂O), it should give approximately 18.01528 grams/mole, matching the example provided.

Key concepts

Carbohydrates

Carbohydrates are essential biomolecules composed mainly of carbon, hydrogen, and oxygen atoms. They have a general formula of \( C_n(H_2O)_m \), where \( n \) and \( m \) are integers. This class of compounds is fundamental in biology as they serve as major energy sources and structural components in organisms.
One key aspect of carbohydrates is their varied structure. They can be simple sugars like glucose, with just one sugar molecule, or complex polysaccharides like starch, composed of long chains of sugar molecules.
Understanding the molecular composition of carbohydrates helps in determining their molecular weight, which is crucial for various chemical and biological processes. By knowing the number of carbon, hydrogen, and oxygen atoms, as found in specific carbohydrates, one can calculate the molecular weight using fixed atomic weights of these elements.

Atomic Weights

Atomic weights, also known as atomic masses, are crucial values used in chemistry to determine the mass of atoms. These weights are typically given in grams per mole, which reflect the mass of a mole of atoms of a given element.
For example:

• Hydrogen (H) has an atomic weight of 1.00794 g/mol.
• Carbon (C) has an atomic weight of 12.0107 g/mol.
• Oxygen (O) has an atomic weight of 15.9994 g/mol.

By using these atomic weights, one can calculate the molecular weight of compounds. For instance, the molecular weight of a water molecule \( H_2O \)—which has two hydrogen atoms and one oxygen atom—can be calculated by: \[2(1.00794) + 15.9994 = 18.01528 \text{ grams/mole}\]Accurate knowledge of atomic weights is essential for scientific experiments and calculations involving molecular compounds.

Python Programming

Python is a highly versatile programming language frequently used for scientific computing and data analysis due to its simplicity and readability. In the context of calculating molecular weights, Python's straightforward syntax allows users to easily input, compute, and output results.
A basic Python program typically includes:

• Prompts for user input using the `input()` function.
• Use of mathematical operators to perform calculations.
• Displaying results using the `print()` function.

This approach ensures that the program is both effective and user-friendly, enabling students and scientists to run calculations quickly and accurately without dealing with overly complex code.

User Input Handling

Handling user input effectively is a critical skill in programming. It involves collecting user data, processing it, and responding accordingly. In Python, this is often managed using the `input()` function, which allows users to enter data which the program then processes.
Considerations for user input handling include:

• Ensuring data type compatibility, such as converting input to integers or floats using `int()` or `float()` functions.
• Validating inputs to prevent errors. For instance, checking that negative numbers or non-numeric inputs aren't submitted when expecting counts of atoms.
• Providing clear and understandable prompts to guide user input effectively.

This ensures that the program functions smoothly and provides accurate results based on user entries, enhancing the user experience and reliability of the software.