//=========================================================================
#define PROGRAMMER "BAHN, William"
#define PROG_CODE  "bahw"
#define COURSE     "ECE-1021"
#define YEAR       (2003)
#define TERM       "Fall"
#define SECTION    (0)
#define ASSIGNMENT "RWA 2.6"
#define REVISION   (0)
#define TITLE      "Real World Application from Section 2.6"
#define SUBTITLE   "Classifying Solutions as Acidic or Nonacidic"
#define EMAIL      "wbahn@eas.uccs.edu"
#define FILENAME   "rwa0206.c"
//=========================================================================

// PROBLEM:
//
// The pH of a solution is given by:
//        pH = -log10(mc)
// where mc is the molar concentation of hydronium ions in gr-atoms/liter.
//
// A solution is alkaline if pH > 7 and acidic if pH < 7
//
// MOD TO TEXT: Classify if Neutral if 6.9 < pH <= 7.1

// Given the molar concentration, compute the pH and classify the
// solution as alkaline or acidic. Print both pH and solution type.

// Continue until user indicates 'End-of-File' by typing Ctrl-Z.

// PSEUDOCODE
// 1) GET: The first molar concentration.
// 2) LOOP: Until the user enters ^Z.
// 2.1) SET: pH = -log10(mc)
// 2.2) PUT: The pH to the screen
// 2.3) IF: pH > 7
// 2.3.1) PUT: The solution is alkaline.
// 2.4) ELSE:
// 2.4.1) PUT: The solution is acidic.
// 2.5) GET: The next molar concentration.
// 3) PUT: Program Termination Message to screen.

//== INCLUDE FILES ========================================================
#include <stdio.h> // printf(), scanf(), EOF
#include <math.h>  // log10()

//== FUNCTION PROTOTYPES ==================================================
void PrintHeader(void);

//== MAIN FUNCTION ========================================================
int main(void)
{
	double pH, mc;

	PrintHeader();
	printf("\n"); // Print a blank line

	printf("Enter Ctlr-Z to quit.\n");
	printf("\n"); // Print a blank line

	printf("Enter the first molar concentration (in gm-atoms/liter): ");
	while(EOF != scanf("%lf", &mc))
	{
		pH = -log10(mc); // Calculate pH per definition
		printf("  pH = %5.2f ", pH);
		if(7.1 < pH)
			printf("(Alkaline)\n");
		else if(6.9 > pH)
			printf("(Acidic)\n");
		else
			printf("(Neutral)\n");
		printf("\n"); // Print a blank line
		printf("Enter the next molar concentration (in gm-atoms/liter): ");
	}

	printf("\n"); // Carriage Return for input line after ^Z is entered.
	printf("\n"); // Print a blank line
	printf("PROGRAM TERMINATED BY USER\n");
	return(0);
}

//== SUPPORT FUNCTIONS ====================================================
void PrintHeader(void)
{
	printf("========================================"
			 "=======================================\n");
	printf("Course....... %s-%i (%s %i)\n", COURSE, SECTION, TERM, YEAR);
	printf("Programmer... %s (%s)\n", PROGRAMMER, PROG_CODE);
	printf("Assignment... %s (Rev %i) (Source Code in %s)\n",
		ASSIGNMENT, REVISION, FILENAME);
	printf("Description.. %s\n", TITLE);
	printf("              %s\n", SUBTITLE);
	printf("========================================"
			 "=======================================\n");

	return;
}