Stoichiometry Calculator
The Stoichiometry Calculator uses mole ratios from balanced chemical equations to determine the amounts of reactants and products. Calculate theoretical yield, identify limiting reagents, and convert between moles, grams, and liters for any reaction.
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What is Stoichiometry?
Stoichiometry is the calculation of quantities in chemical reactions based on balanced equations. The coefficients in a balanced equation give the mole ratio — for 2H₂ + O₂ → 2H₂O, the ratio is 2:1:2, meaning 2 moles of hydrogen react with 1 mole of oxygen to produce 2 moles of water.
Stoichiometric calculations are essential in chemistry for determining how much reagent is needed, predicting product yields, identifying limiting reagents, and calculating percent yield. The mole ratio is the bridge between reactants and products.
Формулы и Используемые Уравнения
В калькуляторе заложены 5 основных уравнений:
1 Mole Ratio Conversion ▼
For 2H₂ + O₂ → 2H₂O: 3 moles H₂ produces 3 × (2/2) = 3 moles H₂O.
2 Moles from Grams ▼
36 grams of water (H₂O, MW=18): Moles = 36 / 18 = 2 moles.
3 Theoretical Yield ▼
Determines the maximum possible product from the limiting reagent.
Как Пользоваться Калькулятором
Чтобы использовать этот Калькулятор Отношений, выполните 3 простых шага:
Введите Данные
Введите известные числа в поля ввода. Оставьте одно поле пустым — калькулятор вычислит это неизвестное значение.
Выберите Режим
Выберите режим работы — Решение пропорций, Упрощение отношений или Масштабирование. В каждом режиме используются свои математические формулы.
Получите Результат
Нажмите кнопку Вычислить. На экране отобразится ответ с цветной шкалой отношения, круговой диаграммой и пошаговым решением.
Примеры Задач с Пошаговыми Решениями
Вот 3 практических примера расчетов с подробным математическим описанием действий:
Ввод 1 How much O₂ needed to react with 4 moles H₂?
Ввод 2 Theoretical yield from 10g CH₄ burning in excess O₂
Ввод 3 Find limiting reagent: 5 mol H₂ and 4 mol O₂
Часто Задаваемые Вопросы
What is a mole ratio? ▼
A mole ratio is the ratio of coefficients in a balanced equation. For N₂ + 3H₂ → 2NH₃, the mole ratios are N₂:H₂ = 1:3, H₂:NH₃ = 3:2, and N₂:NH₃ = 1:2.
What is a limiting reagent? ▼
The limiting reagent is the reactant that runs out first, determining the maximum product yield. The other reactant is 'in excess.' Identify it by dividing each reactant's moles by its coefficient — the smallest quotient is the limiting reagent.
How do you calculate percent yield? ▼
Percent Yield = (Actual Yield / Theoretical Yield) × 100. If you expected 50g of product but obtained 42g: Percent Yield = (42/50) × 100 = 84%.
Why must chemical equations be balanced for stoichiometry? ▼
Balanced equations obey the law of conservation of mass — atoms are neither created nor destroyed. Unbalanced equations give incorrect mole ratios and wrong calculations.
How do you convert between moles and grams? ▼
Multiply moles by molar mass to get grams. Divide grams by molar mass to get moles. Example: 3 moles of NaCl (MW=58.44) = 3 × 58.44 = 175.3 grams.