Mol Calculator User Manual

V2.08

Revision history

V1.00	Initial release.
V1.01	Corrected the text error of formula. Coef(1) x n(1) = Coef(2) x n(2) = Coef(3) x n(3) = Coef(4) x n(4) = Coef(5) x n(5) -> n(1)/Coef(1) = n(2)/Coef(2) = n(3)/Coef(3) = n(4)/Coef(4) = n(5)/Coef(5) Executable code is the same as V1.00.
V2.00	Added the following buttons: P_Pres button, G_Vol button, and PresVol selector button. Extended so that either pressure data or volume data belongs to P button data group.
V2.01	Modified the volume of gas at the standard temperature and pressure (0 ℃, 1 atm) to 22.414 L from 22.4 L.
V2.02	Added description about the integrity of displayed data.
V2.03	Corrected the character string in help to "22.414" from "22.4".
V2.04	Corrected pressure output data at [kPa] and [mmHg] unit for the pressure mode P button calculation.
V2.05	Updated for iOS7 and the new SDK of Xcode5. The status bar was hidden.
V2.06	Updated for iOS8 and the new SDK of Xcode6.
V2.07	Updated for iOS9 and the new SDK of Xcode7.
V2.08	Updated for iOS10 and the new SDK of Xcode8. Added explanation to the PresVol mode and the P button data group

1. Overview

Mol calculator is a calculation sheet that solves chemical mol calculation problems.

A typical problem is as follows.

(Example)

The hydrogen gas used for a fuel cell is generated from aluminum powder particles and water. (1) When the temperature is 20 ℃ and the pressure is 1 atmosphere, how much liters of hydrogen gas can be generated from 1 g of aluminum? (2) When the gas is generated in a closed container of 0.1 liter at the temperature of 20 ℃, how much is the pressure of hydrogen gas?

(1) Volume calculation

Mol calculator solves the problem in the following three steps.

Prepare chemical equations and atomic (molecular) weights. They are basics for the calculation.

They are as follows.

2Al + 6H2O -> 2Al(OH)3 + 3H2

Atomic weight of Al = 27 [g/mol]

Molecular weight of H2 = 2 [g/mol]

Enter known data into the Mol sheet.

Rows correspond to substances. Columns correspond to the attributes of substance.

First row

Name = Al, Coef = 2, Aw = 27, W = 1

Second row

Name = H2, Coef = 3, Aw = 2, T = 20[C], p = 1[atm]

Attribute data are not independent but mutually related by formulae.

Calculation is a conversion from unknown data to known data using the formulae.

The formulae are embedded in P and G buttons.

Touching out those buttons executes the formulae and changes unknown data to known data.

Touch out buttons as follows.

Touch out P_W button of the first row. Mol data are changed to known data.

Touch out P_Mol button of the second row. Vol data are changed to known data.

It turns out that the volume of hydrogen gas is 1.3 L.

(2) Pressure calculation

Use the above results.

Enter the following data in the second row.

Vol = 0.1[L]

Touch out G_Pres button of the second row. Pressure data are changed to known data.

It turns out that the pressure of hydrogen gas is 13.36 atmosphere.

Change PresVol mode to pressure mode.

Enter the following data.

First row

Name = Al, Coef = 2, Aw = 27, W = 1

Second row

Name = H2, Coef = 3, Aw = 2, T = 20[C], Vol = 0.1[L]

Touch out buttons as follows.

Touch out P_W button of the first row. Mol data are changed to known data.

Touch out P_Mol button of the second row. Pres data are changed to known data.

It turns out that the pressure of hydrogen gas is 13.36 atmospheres.

2. Data label

Name: Substance name (option).

Coef: Substance coefficient of chemical equation.

This defines quantity ratio among substances.

When a chemical equation is aX + bY -> cZ, then a, b, and c are coefficients.

When the Coef text of the data field is not numeric, it is interpreted as zero value.

Aw [g/mol]: Atomic or molecular weight of substance

n [mol]: Mol quantity of substance.

W [g]: Weight of substance.

StdVol [L]: Gas volume of substance at 0 deg C and 1 atm.

T [C][F]: Temperature.

p [atm][kPa][mmHg]: Gas pressure.

Vol [L]: Gas volume of substance at the temperature T and at the pressure p.

3. Buttons and data

P (put) button inputs data to which the P button is assigned.

P button data group is a group of data to which the P buttons are assigned. The P button data group has a special character. When one P data is input, all other data of the P button data group are updated by formulae. Ｗhen the P button is touched out, Mol data of other rows are also updated by use of Coef data.

When the data field is blank, it is interpreted as illegal data.

When the data field is illegal character, it is interpreted as zero value.

Number of input data: number of output data = 1: N, where N > 1.

G (get) button gets data from other data using formulae.

When the data field is blank, it is interpreted as illegal data.

When the data field is illegal character, it is interpreted as zero value.

Number of input data: number of output data = N: 1, where N > 1.

The manual modification of data may break the integrity of displayed data. However, G_button and P_button executions performed succeeding later recover the integrity of displayed data.

C (Clear) button clears all row data.

Either pressure data or volume data belongs to P button data group.

See Appendix 1.

The PresVol button specifies pressure mode or volume mode.

In pressure mode, pressure data belongs to P button data group. And, the P_Pres button is displayed.

In volume mode, volume data belongs to P button data group. And, the P_Vol button is displayed.

The default mode is volume mode.

P button data represents substance quantity.

PresVol mode determines the P button data group.

In the Pres mode, elements of the P button data group are n[mol], W[g], StdVol[L], and p[atm][kPa][mmHg].

In the Vol mode, elements of the P button data group are n[mol], W[g], StdVol[L], and Vol[L].

The difference is below.

In the Pres mode, p[atm][kPa][mmHg] is an element of the P button data group ..

In the Vol mode, Vol[L] is an element of the P button data group .

4. Color change

Touching out a button executes calculation and generates output data from the input and the referenced data. Unknown data are changed to known data.

Color change shows what data are input, output, or referenced data in this button execution.

Input data: Blue color

Referenced data: Yellow color

Output data: Green color

Uncalculated data: Red color

Referenced data is an input data that is referenced at the P button execution.

Uncalculated data is an output data that is not normally calculated. This uncalculated data is not output. The former data is remains unchanged in this data field.

5. Formulae

Embedded formulae are as follows.

n = W / Aw

StdVol = 22.414 x n

StdVol /273.15 = p x Vol / (T + 273.15)

n(1)/Coef(1) = n(2)/Coef(2) = n(3)/Coef(3) = n(4)/Coef(4) = n(5)/Coef(5)

6. Features

This software solves the problem not as a black box but as a white box. You need to think the process of solving a problem. This makes your knowledge refresh. The black box solution is convenient; however it has a risk of losing your knowledge. This software has few such risks.

7. Examples

(Example-1) Calculation of molecular weight

There is 639 mL of gas at the temperature 27 degC and the pressure 1 atom.

The weight of the gas is 2.13 g. How much is the molecular weight of the gas?

Gather known data.

Enter known data into the Mol sheet.

First row

W = 2.13, T = 27[C], p = 1[atm], Vol = 0.639[[L]

Touch out P_Vol button of the first row. Mol data are changed to known data.

Touch out G_Aw button of the first row. Atomic weight (molecular weight) data are changed to known data.

It turns out that the molecular weight of the gas is 82 g/mol.

Appendix 1. Classification of data

Physical and chemical data are classified into non-substance data and substance data.

The non-substance data is a data that does not depend on substance.

(Example) Time, voltage

The substance data is a data that depends on substance, i.e., that is property data of substance.

Moreover the substance data is classified into intensive data and extensive data.

The intensive data is a data that does not depend on substance quantity.

(Example) Atomic weight, density, concentration

The extensive data is a data that depends on substance quantity.

(Example) Mol, weight, volume, charge

The P button data group of this software corresponds to the extensive data group.

This classification varies with application.

For the gas within a balloon container, the gas pressure is considered to be the intensive data and the volume is considered to be the extensive data.

For the gas within an airtight container, the gas pressure is considered to be the extensive data and the volume is considered to be the intensive data.