CalcOpenly
한국어

Grams to moles and stoichiometry calculator

Convert grams to moles and particles for any chemical formula, and find the limiting reagent, theoretical yield and leftover excess of a balanced reaction.

업데이트 검증한 예제: 7

Used for the amount you type and the amount in the result
시도하기
Amount
mol
Amount: 2 mol
유효 자릿수: 6; 가장 가까운 값, 중간값은 0에서 먼 쪽으로
질량
36.03g
Particles
1.20443 × 10²⁴
Molar mass used
18.015g/mol

36.03 g of H₂O is 2 mol, or 1.204 × 10²⁴ particles.

Mass, amount and particles of H₂O

질량36.03 gAmount2 molParticles1.204 × 10²⁴÷ 18.015 g/mol× 18.015 g/mol× 6.022 × 10²³÷ 6.022 × 10²³
계산 방법 S

  1. Amount in moles

    n=mM=36.0318.015=2 moln = \frac{m}{M} = \frac{36.03}{18.015} = 2\ \mathrm{mol}

  2. 질량

    m=nM=(2)(18.015)=36.03 gm = nM = (2)(18.015) = 36.03\ \mathrm{g}

  3. Particles

    N=nNA=(2)(6.02214076×1023)=1.20443×1024N = nN_A = (2)(6.02214076\times10^{23}) = 1.20443 \times 10^{24}

    N_A is exact in the SI since 2019.

Grams to moles and stoichiometry calculator 소개

The amount of substance links mass to particle count: n = m/M, where M is the molar mass worked out from the formula, and N = n × N_A, where the Avogadro constant N_A is 6.022 140 76 × 10²³ per mole. In limiting-reagent mode, each reactant's moles are divided by its coefficient in the balanced equation; the smallest quotient is how far the reaction can run, and it sets the theoretical yield of product.

Typical uses are weighing out reagents and predicting product mass before an experiment. The default, 36.03 g of water, is 2 mol, or 1.204 × 10²⁴ molecules. For 2 H₂ + O₂ → 2 H₂O with 10 g of hydrogen and 64 g of oxygen, oxygen runs out first and the yield is 72.06 g of water.

The yield assumes the equation is balanced and the reaction goes to completion, so measured yields come out lower.

계산 예제

36.03 g of water is 2 mol

Calculate
Grams ↔ moles ↔ particles
Molar mass from
공식
공식
H2O
I have
질량
질량
36.03 g
Amount unit
mol
Amount
2 mol
Particles
1.20443 × 10²⁴

검증 출처: Python 3.8 decimal: 36.03 / 18.015 = 2; × 6.02214076e23 (IUPAC 2021 weights)

One mole of carbon atoms

Calculate
Grams ↔ moles ↔ particles
Molar mass from
공식
공식
C
I have
Moles
Amount
1
Amount unit
mol
Particles
6.02214 × 10²³
질량
12.011 g

검증 출처: SI 2019 definition of the mole (Avogadro constant exact); standard atomic weight of carbon 12.011 (IUPAC 2021)

0.25 mol NaCl with a typed molar mass

Calculate
Grams ↔ moles ↔ particles
Molar mass from
Typed value
몰 질량
58.44 g/mol
I have
Moles
Amount
0.25
Amount unit
mol
질량
14.61 g

검증 출처: Python 3.8 decimal: 0.25 × 58.44

3.011 × 10²³ molecules of CO₂

Calculate
Grams ↔ moles ↔ particles
Molar mass from
공식
공식
CO2
I have
Particles
Amount unit
mol
Number of particles
3.011e23
Amount
0.499988 mol
질량
22.004 g

검증 출처: Python 3.8 decimal: 3.011e23 / N_A = 0.4999883; × 44.009 g/mol

자주 묻는 질문

How do you convert grams to moles?

Divide the mass in grams by the molar mass in g/mol: n = m/M. Water has a molar mass of 18.015 g/mol, so 36.03 g of water is 36.03 ÷ 18.015 = 2 mol. To go back, multiply moles by the molar mass. The molar mass is the sum of the atomic weights in the formula, which the calculator adds up from IUPAC 2021 values.

What is Avogadro's number?

It is the number of particles in one mole: exactly 6.022 140 76 × 10²³ per mole since the 2019 revision of the SI, which defines the mole by fixing this constant. One mole of carbon therefore contains 6.022 140 76 × 10²³ atoms and weighs 12.011 g. Multiply an amount in moles by this number to get molecules, atoms or formula units.

How do you find the limiting reagent?

Convert each reactant's mass to moles, then divide by its coefficient in the balanced equation; the reactant with the smaller result runs out first. For N₂ + 3 H₂ → 2 NH₃ with 28 g of N₂ and 6 g of H₂, nitrogen gives 0.9995 mol ÷ 1 = 0.9995 and hydrogen gives 2.976 mol ÷ 3 = 0.992, so hydrogen limits the yield to 33.79 g of ammonia.

What is the difference between theoretical yield and percent yield?

Theoretical yield is the product mass if the limiting reagent reacted completely, which is what this calculator reports. Percent yield compares what you actually collected: actual ÷ theoretical × 100. With a theoretical yield of 72.06 g of water and 65.0 g collected, the percent yield is 90.2 %. Transfer losses, side reactions and incomplete reaction keep real yields below 100 %.

“Grams to moles and stoichiometry calculator”의 정확도는 어느 정도인가요?

정확도는 입력값과 계산 방법의 가정에 따라 달라집니다. 십진 연산은 유효숫자 50자리를 사용하지만, 추정값·수치해석 방법·원본 데이터의 정밀도는 더 낮을 수 있습니다. 표시값을 반올림해도 이러한 한계는 사라지지 않습니다. 독립적인 출처의 풀이와 대조한 계산 예시: 7. 예를 들어 “36.03 g of water is 2 mol”은 Python 3.8 decimal: 36.03 / 18.015 = 2; × 6.02214076e23 (IUPAC 2021 weights)와 대조해 확인합니다.

이 계산 방법의 출처는 무엇인가요?

CODATA 2022 / SI 2019 — Avogadro constant N_A = 6.022 140 76 × 10²³ mol⁻¹ (exact); OpenStax Chemistry 2e, §4.4 Reaction yields (limiting reactant, theoretical yield).

이 계산기 소개

n=mM,N=nNA;ξ=min⁡ ⁣(nAa,nBb),mproduct=c ξ Mproductn = \frac{m}{M},\quad N = nN_A;\qquad \xi = \min\!\left(\frac{n_A}{a}, \frac{n_B}{b}\right),\quad m_{\text{product}} = c\,\xi\,M_{\text{product}}

출처

  1. CODATA 2022 / SI 2019 — Avogadro constant N_A = 6.022 140 76 × 10²³ mol⁻¹ (exact)
  2. OpenStax Chemistry 2e, §4.4 Reaction yields (limiting reactant, theoretical yield)

출처와 대조하여 검증

이 계산기에는 독립적인 출처에서 답을 얻은 계산 예제가 7개 있습니다. 테스트 모음에서 실행되며 여기에서도 실행할 수 있습니다.

관련 계산기