Equilibrium

EquilibriumModel is a reaction in a closed vessel. Each species has a name, a coefficient (negative for a reactant) and a starting concentration in mol/L. The mixture moves along the reaction to where the reaction quotient Q equals k, closing in by a factor of e every settle seconds. disturb(at, species, delta) adds or removes some of a species later, and the mixture settles again, as Le Chatelier’s principle says. concentrations(seconds) and quotient give the numbers.

Equilibrium shows the concentrations as bars, reactants in reactant_color and products in product_color, starting the model’s clock at delay. With labels each bar has its formula under it (the digits set as subscripts) and its concentration over it. A line above compares Q with K: whether the reaction runs forward, runs in reverse or is at equilibrium. Gallery scene: Equilibrium (hydrogen iodide, then more hydrogen).

Equilibrium 7 sPlayUnmuteCopy render command

use fframes_kit::prelude::*;

let model = EquilibriumModel::new(&[("H2", -1, 1.0), ("I2", -1, 1.0), ("HI", 2, 0.0)], 49.0, 0.5)
    .disturb(3.0, 0, 1.0);
// settled again long after the extra hydrogen
assert!((model.quotient(&model.concentrations(30.0)) - 49.0).abs() < 1e-6);

fn figure<'a>(ui: &mut Ui<'a, '_, '_>, model: &'a EquilibriumModel) -> Svgr<'a> {
    ui.show(Equilibrium {
        model: Some(model),
        delay: 0.5,
        ..ui.defaults()
    })
}

API

Components are plain structs. Set the fields you need and fill the rest with ..ui.defaults(): the defaults below come from the current theme (theme. values are fields of Theme).

Equilibrium

Field	Type	Default	Description
model	Option<&EquilibriumModel>	None	The EquilibriumModel whose concentrations are drawn; None draws nothing.
delay	f32	0.0	Seconds after the container’s start when the model’s clock starts.
center	(f64, f64)	(0.0, 0.0)	The middle of the bar area, in units of ui.space.
width	f32	900.0	Width in pixels of the bar area, shared equally between the species.
height	f32	420.0	Height in pixels of the bar area, the bar height at max mol/L.
max	Option<f64>	None	Concentration in mol/L that fills the full height; None uses the model’s highest concentration.
labels	bool	true	Writes each species name and concentration and the Q against K line; false for bare bars.
reactant_color	Color	theme.colors.accent	Colour of the bars of reactants (negative coefficient).
product_color	Color	theme.colors.highlight	Colour of the bars of products (positive coefficient).
axis_color	Color	theme.colors.muted	Colour of the baseline under the bars.
text_color	Color	theme.colors.text	Colour of the names, concentrations and the Q/K line.
equal_color	Color	Color::hex("#69db7c")	Colour of the Q/K line once the mixture is at equilibrium.
stroke_width	f32	theme.stroke.regular	Width in pixels of the baseline.
enter	Option<EnterAnim>	None	How the baseline draws; None shows it from the start.
exit	Option<ExitAnim>	None	How the baseline leaves at the end of the container; None stays.
parts_enter	Option<FadeIn>	None	Fade in of the bars and labels; None for none.
parts_exit	Option<FadeOut>	None	Fade out of the bars and labels before the end; None for none.

Feature chemistry · Source