Thermochemistry vs Column Construction Calculator

Thermochemistry helps in evaluation of enthalpy or heat release/absorption of a system undergoing numerous temperature changes and phase transitions. The calculations take advantage of known values of heat capacity at constant pressure (Cp) and molar or per gram enthalpy of phase transition. Amount of compound can be defined in grams or moles, in a way that Cp and enthalpy units would match. App provides enthalpy values for each step. Negative enthalpy points to exothermic process – heat release, while positive one to endothermic - heat absorption. °C and K are interchangeable. Calorimetry section provides means for evaluation of the heat capacity of calorimeter and for finding equilibrium temperature of mixed system. Forward arrow button sets the final temperature of the mixture. Backward arrow button sets missing temperature or heat capacity of one of the components. Enthalpy values show heat flow for each component. Example of problems solved by application (screenshots): Problem 1: Calculate the amount of energy required to change 100.0 g of ice at -15.0 °C to steam at 125.0 °C. Known values: Heat of melting = 334.16 J g¯1 Heat of vaporization = 2259 J g¯1 specific heat capacity for solid water (ice) = 2.06 J g¯1 K¯1 specific heat capacity for liquid water = 4.184 J g¯1 K¯1 specific heat capacity for gaseous water (steam) = 2.02 J g¯1K¯1 Solution: 1) Heating of 100.0 g of ice from -15.0°C to 0.0°C: (100.0 g) (15.0 K) (2.06 J g¯1 K¯1) = 3090 J 2) Melting of 100.0 g of ice: (100.0 g) (334.16 J g¯1) = 33416 J 3) Heating of 100.0 g of liquid water from zero to 100.0 Celsius: (100.0 g) (100.0 K) (4.184 J g¯1 K¯1) = 41840 J 4) Evaporations of 100.0 g of liquid: (100.0 g) (2259 J g¯1) = 225900 J 5) Heating of 100.0 g of steam from 100.0 to 125.0 Celsius: (100.0 g) (25.0 K) (2.02 J g¯1 K¯1) = 5050 J 6) Summation of the results: 3090 + 33416 + 41840 + 225900 + 5050 = 309.3 kJ Problem 2: Determine the heat capacity of a coffee-cup calorimeter. During calibration 100.0 g of water at 58.5 °C has been added to 100.0 g of water, already in the calorimeter, at 22.8 °C. Calculate the heat capacity of the calorimeter in J/°C, if final temperature of the water is 39.7 °C. (Specific heat of water is 4.184 J/g °C.) Solution: 1) Heat given up by warm water: q = (100.0 g) (18.8 °C) (4.184 J/g °C) = 7865.92 J 2) Heat absorbed by water in the calorimeter: q = (100.0 g) (16.9 °C) (4.184 J/g °C) = 7070.96 J 3) The difference was absorbed by the calorimeter: 7865.92 - 7070.96 = 794.96 J 4) Calorimeter constant: 794.96 J / 16.9 °C = 47.0 J/°C Problem 3: Determine the final temperature when 10.0 g of aluminum at 130.0 °C mixes with 200.0 grams of water at 25.0 °C. Please note the starting temperature of the metal is above the boiling point of water. In reality, the sample may vaporize a tiny amount of water, but we will assume it does not for the purposes of the calculation. Solution: 1) The colder water will warm up and the warmer metal will cool down. The whole mixture will equilibrate up at the same temperature. The energy which "flowed" out of the warmer metal equals the energy which "flowed" into the colder water: Qaluminum = Qwater (10) (130 - x) (0.901) = (200.0 )(x - 25) (4.18) 117.13 - 0.901x = 83.6x - 2090 x = 26.12 °C. Important! Water didn’t cross temperature of phase transition – vaporization; otherwise calculation would be more complex. Calculation of reaction standard Gibbs free energy: For the general reaction aA + bB -> cC + dD ΔG°rxn = cΔGf°(C) + dΔGf°(D) - aΔGf°(A) - bΔGf°(B) Example: Calculate the Gibbs free energy for the following reaction at 25 °C. Cu (s) + H2O (g) -> CuO (s) + H2 (g) ΔG°rxn = ΔGf°(CuO (s)) – ΔGf°(H2O (g)) = (–129.7 kJ/mol) – (–228.6 kJ/mol) = 98.9 kJ/mol ΔGf° = 0; for elements in their standard state by definition. At equilibrium, ΔG = 0! Important points Application uses dot as a decimal separator. Special attention should be paid for units’ consistency.

Column Construction Calculator contains 35 calculators to measure and calculate different column and civil engineering parameters. NEW — Built-in Reference Library Look up standard material properties and auto-fill them straight into any calculator: • Steel — ASTM grades (A36, A992 W-shapes, A572 Grade 50, A500 Grade B & C HSS, A53 Grade B Pipe) with Yield Strength (Fy) and Modulus of Elasticity (E) • Aluminum — common structural aluminum grades • Concrete — ACI mix classes from 2500 psi to 10000 psi with compressive strength (f'c), modulus (Ec) and β₁ factor Available in Metric (SI) and Imperial (USCS) Units Column Calculator contains the following 35 Calculators: • Critical Buckling Load - Column Pivoted at Both Ends (Euler's Formula) • Critical Buckling Load - One End Fixed and Other End Rounded (Euler's Formula) • Critical Buckling Load - Both Ends Fixed (Euler's Formula) • Critical Buckling Load - One End Fixed and Other End Free (Euler's Formula) • Nominal Bearing Strength of Concrete (Column Base Plate Design) • Area of Base Plate for Factored Load • Length of Rectangular Base Plate (Wide-Flange Column) • Width of Base Plate - Parallel to the Flanges • Projection of Base Plate beyond the Flange and Parallel to the Web (m) • Projection of Base Plate beyond the Edges of the Flange and Perpendicular to the Web (n) • Equivalent Cantilever Dimension (n') • Column Base Plate Design Value (Lambda) • Column Base Plate Design Value (X) • Thickness of Base Plate (m) • Thickness of Base Plate (n) • Thickness of Base Plate (Lambda n') • Area of the Column • Allowable Bearing Pressure on Support (Base Plate occupies Full Area of Support) • Allowable Bearing Pressure on Support (Base Plate covers less than Full Area of Support) • Wall Thickness of Steel Pipe (Width of Face of Rectangular Section) • Wall Thickness of Steel Pipe (Outside Diameter of Circular Section) • Design Strength of Axially Loaded Composite Column • Design Strength of Concrete (Direct Bearing) • Effective Length Factor • Slenderness Ratio • Critical Buckling Load • Elastic Critical Buckling Load • Allowable Design Load – Aluminum Columns • Allowable Design Load – Aluminum Columns (Johnson's Equation – Straight Line) • Allowable Design Load – Aluminum Columns (Johnson's Equation – Squared Parabolic) • Ultimate Strength of Column - Zero Eccentricity of Load • Axial Load Capacity – Short Rectangular Members • Balanced Moment • Eccentricity – Balanced Condition • Eccentricity – Slender Columns