The qty function makes it easy to keep track of different quantities in chemical calculations. Metric prefixes are fully supported, i.e. any unit can be combined with standard metric scaling (mL, nmol, kg, etc.). Some quantities can also be used in common arithmetic operations.

qty(x, unit, scale_to_best_metric = TRUE)

is_qty(q)

is_amount(q)

is_mass(q)

is_molecular_mass(q)

is_molarity(q)

is_density(q)

is_volume(q)

is_pressure(q)

is_solubility(q)

is_temperature(q)

Arguments

x

the numeric value of the quantity, can be a single value or a vector

unit

the unit of the quantity

scale_to_best_metric

whether to automatically scale to the best metric prefix

q

a quantity object

Details

amount: base unit mol but also understands mole, all metric prefixes allowed

mass: base unit g, all metric prefixes allowed

molecular mass: base unit g/mol, all metric prefixes allowed in the numerator

concentration (molarity): base unit M but also understands mol/L, all metric prefixes allowed in the numerator

concentration (density): base unit g/L but also understands g/l, all metric prefixes allowed in the numerator

volume: base unit L but also understands l, all metric prefixes allowed

pressure: base unit bar but also understands Pa, all metric prefixes allowed, the common non-metric units atm, psi, Torr, mTorr, and % SP (% at standard pressure = % of 1 bar) are also supported and will be automatically converted to bar.

Henry's law solubility constant: base unit M/bar, all metric prefixes allowed in the numerator, the common non-metric unit M/atm is also supported and will be automatically converted to M/bar.

temperature: base unit K but also understands C and F and converts them to Kelvin

Functions

  • qty: generate a quantity object

  • is_qty: check whether something is a quantity

  • is_amount: check whether something is an amount quantity

  • is_mass: check whether something is an amount quantity

  • is_molecular_mass: check whether something is a molecular mass quantity

  • is_molarity: check whether something is a molarity quantity

  • is_density: check whether something is a density quantity

  • is_volume: check whether something is a volume quantity

  • is_pressure: check whether something is a pressure quantity

  • is_solubility: check whether something is a solubility quantity

  • is_temperature: check whether something is a temperature quantity

See also

Other quantity functions: metric, quantity_info

Examples

qty(0.045, "mmol/L")
#> Molarity [µM] #> [1] 45
qty(200, "mbar")
#> Pressure [mbar] #> [1] 200
qty(6, "psi")
#> Pressure [mbar] #> [1] 413.6855
qty(30, "C")
#> Temperature [K] #> [1] 303.15
qty(100, "K")
#> Temperature [K] #> [1] 100
qty(5, "mg/L")
#> Density [mg/L] #> [1] 5
qty(1, "mM/bar")
#> Solubility [mM/bar] #> [1] 1
qty(257, "g/mol")
#> MolecularMass [g/mol] #> [1] 257