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.
🕐 Recent Calculations
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.
Fórmulas e Equações Utilizadas
Esta Stoichiometry Calculator usa 5 equações principais:
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.
Como Usar esta Calculadora
Para usar esta Calculadora de Proporção, siga 3 passos:
Insira os Valores
Digite os valores conhecidos nos campos de entrada. Deixe um campo vazio — esse é o valor desconhecido que a Calculadora de Proporção irá resolver.
Escolha o Modo
Selecione o modo de proporção — Resolver, Simplificar ou Redimensionar. Cada modo aplica equações diferentes aos seus valores de entrada.
Obtenha os Resultados
Clique em Calcular. A tela de resultados exibe a resposta com uma barra de proporção visual, um gráfico de pizza e um detalhamento da solução passo a passo.
Problemas de Exemplo e Soluções Passo a Passo
Aqui estão 3 problemas de exemplo com soluções passo a passo usando esta Calculadora de Proporção:
Entrada 1 How much O₂ needed to react with 4 moles H₂?
Entrada 2 Theoretical yield from 10g CH₄ burning in excess O₂
Entrada 3 Find limiting reagent: 5 mol H₂ and 4 mol O₂
Perguntas Frequentes
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.