Mole Ratio Calculator with Steps (Molar Ratio) | StatsUnlock

To calculate a mole ratio, balance the equation and read the coefficients: in N₂ + 3H₂ → 2NH₃ the mole ratio of N₂ : H₂ : NH₃ is 1 : 3 : 2. To convert, multiply the moles you have by (coefficient wanted ÷ coefficient given):

Rule of thumb: mole ratios come from coefficients, never from subscripts or masses. For an experimental mole ratio, convert each mass to moles and divide by the smallest: 1.27 g Cu and 4.32 g Ag give 0.01999 : 0.04005 = 1 : 2.00. For DNA cloning, insert ng = vector ng × (insert bp ÷ vector bp) × ratio, so 50 ng of a 3000 bp vector needs 50.0 ng of a 1000 bp insert at 3 : 1.

A mole ratio (also called a molar ratio or mole-to-mole ratio) is the ratio between the amounts, in moles, of two substances in a reaction. It comes from the coefficients of the balanced chemical equation: N₂ + 3H₂ → 2NH₃ says that 1 mol of nitrogen reacts with 3 mol of hydrogen to give 2 mol of ammonia, whatever the scale. That is why mole ratios are central to every stoichiometric calculation: they are the only bridge between one substance and another.

A mole ratio calculator balances the equation for you, lists all possible mole ratios, and converts an amount of one substance (in moles, grams, mL of solution, litres of gas or particles) into the moles and grams of every other substance. It can also work backwards from the lab: from measured masses to an experimental mole ratio, or from two masses and molecular weights to the molar ratio of two compounds. For molecular biology it gives the insert : vector molar ratio used in ligation, In-Fusion and Gibson or NEBuilder assembly.

A worked one-liner: how many moles of oxygen react with 5.0 mol of hydrogen? 2H₂ + O₂ → 2H₂O gives O₂ : H₂ = 1 : 2, so 5.0 × 1/2 = 2.5 mol O₂.

Who uses it: mole ratios are taught in NCERT Class 11 (“Some Basic Concepts of Chemistry”), GCSE, A level, AP Chemistry and IB, and asked in JEE, NEET and the MCAT. Lab students use experimental mole ratios to identify a reaction or a hydrate; molecular biologists set up ligations with an insert : vector molar ratio every week.

What this free mole ratio calculator solves

One tool covers every mole ratio calculation in a chemistry course and a cloning lab: a mole to mole ratio calculator, an all possible mole ratios calculator, a stoichiometry mole ratio calculator, a molar ratio calculator for two compounds from molecular weight, an experimental mole ratio calculator, and a DNA molar ratio calculator for ligation and In-Fusion cloning. Press Try it to load an example, then press the button to see the working.

Free, with no sign-up. Everything runs in your browser: nothing you type is sent to a server or stored.

En español: ¿cómo se calcula la relación molar? Balancea la ecuación y usa los coeficientes: en N₂ + 3H₂ → 2NH₃, 6,00 mol de H₂ × 2/3 = 4,00 mol de NH₃.

How accurate is this mole ratio calculator?

Equations are balanced exactly with whole-number coefficients, and molar masses use the CIAAW 2024 standard atomic weights (Prohaska et al., 2022). Answers are given to the number of significant figures in your data. Every answer is checked before it gets the Verified badge: the equation must conserve mass, and every amount divided by its coefficient must give the same extent of reaction. For DNA, molecular weights use 617.96 g/mol per base pair plus 36.04 g/mol, the average for double-stranded DNA used by vendor calculators. The R and Python scripts in Sections 10 and 11 return the same 4.00 mol NH₃ and 1 : 2 Cu : Ag ratio as the headline problems.

Research on stoichiometry finds that most student errors come from using the mole ratio the wrong way up or from using masses in place of moles, not from the arithmetic (Schmidt & Jignéus, 2003; Gulacar et al., 2013). That is why the steps always show the ratio as a fraction with its units.

4.1 Why are mole ratios central to stoichiometric calculations?

A balanced equation describes the reaction in particles: one N₂ molecule with three H₂ molecules gives two NH₃. A mole is a fixed number of particles (6.022 × 10²³), so the same 1 : 3 : 2 ratio holds for moles. That makes the mole ratio the only link between two substances: grams, litres, molarity and particles must all be turned into moles, passed through the mole ratio, and turned back. Explaining the significance of the mole ratio in stoichiometric calculations comes down to this: without it you cannot get from what you have to what you want. A mole ratio calculator simply makes that bridge visible for every pair of substances at once.

4.2 How are mole ratios used in chemical calculations?

Write the ratio as a fraction with the substance you want on top and the one you have on the bottom, so the units cancel: 6.00 mol H₂ × (2 mol NH₃ ÷ 3 mol H₂) = 4.00 mol NH₃. The full road map is grams → moles (÷ M) → moles of the other substance (× mole ratio) → grams (× M). The mole ratio is also how you find the limiting reagent: divide the moles of each reactant by its coefficient, and the smallest runs out first.

4.3 Is a mole ratio the same as a mass ratio?

Mole ratios are not mass ratios. In N₂ + 3H₂ → 2NH₃, the mole ratio N₂ : H₂ is 1 : 3, but the mass ratio is 28.014 : 6.048, about 4.6 : 1. Equal masses of NaCl and KCl contain different numbers of moles (0.171 and 0.134 mol in 10.0 g), so their molar ratio is 1.28 : 1, not 1 : 1. The mole ratio calculator always shows both, so the difference is clear.

4.4 What is an experimental mole ratio?

An experimental mole ratio is measured, not read from an equation. Divide each amount of moles by the smallest, then round. A value close to .5, .33 or .25 is a signal to multiply all the numbers by 2, 3 or 4 before rounding. In the mole ratio calculator, type the expected ratio to get the percent difference; comparing the two tells you how well the experiment went:

4.5 Hydrates and formulas

The same arithmetic gives the water of crystallisation of a hydrate: 1.60 g of anhydrous CuSO₄ and 0.90 g of water driven off give 0.01002 : 0.0500 = 1 : 4.98, so the formula is CuSO₄·5H₂O. The experimental mode of the mole ratio calculator does this rounding for you. An empirical formula is an experimental mole ratio of atoms: 2.00 g Fe and 0.860 g O give 1 : 1.50 = 2 : 3, so Fe₂O₃.

4.6 What molar ratio should you use for DNA cloning?

In ligation and assembly reactions, what matters is the number of DNA molecules, so the ratio is a molar ratio. Because a 1000 bp insert has a third of the mass per molecule of a 3000 bp vector, a 3 : 1 insert : vector molar ratio needs equal masses: 50 ng of each. Common starting points are 3 : 1 for T4 DNA ligase, 2 : 1 for In-Fusion (Takara) and NEBuilder HiFi assembly, and 3–5 : 1 or more for fragments under about 350 bp; vendors stress that these are starting points to optimise. The DNA mode of the mole ratio calculator has buttons for each of these presets.

4.7 Whole-number and fractional ratios

Mole ratios from an equation are usually given as the smallest whole numbers, but fractions are just as correct for calculations: H₂ : O₂ = 2 : 1 is the same as 1 : 0.5. The mole ratio calculator gives each ratio both ways, so you can use whichever fraction makes the units cancel.

4.8 A field note on where mole ratio problems go wrong

Marking stoichiometry, the same slips come up: using an unbalanced equation, reading the ratio from subscripts (the 2 in H₂) instead of coefficients, putting the ratio upside down, multiplying grams by the mole ratio, and rounding an experimental 1 : 1.5 to 1 : 2 instead of doubling it to 2 : 3. Writing units on every number stops most of them (Dori & Hameiri, 2003).

▶ Solve a problem above to fill all five cards with your own answer.

The mole ratio formula is n_B = n_A × (b ÷ a), where a and b are the coefficients of A and B in the balanced equation. The other cards feed into it or use it.

This flowchart shows how to calculate mole ratios and use them, exactly as the mole ratio calculator does, on the same problem used in the Excel, R, Python and by-hand sections: nitrogen and hydrogen make ammonia. How many moles and grams of NH₃ form from 6.00 mol of H₂?

Check any box yourself: the Excel sheet in Section 9, the R script in Section 10 and the Python script in Section 11 all return 4.00 mol and 68.1 g of NH₃ for this problem.

1. Choose what you have. A chemical equation, measured amounts for an experimental ratio, two compounds, or a DNA vector and insert.
2. Type the equation. Write N2 + H2 -> NH3; it is balanced for you and the balanced form appears under the box.
3. Pick the substance you have and the one you want. Choose “every other substance” to convert to all of them at once.
4. Enter the amount and unit. Use mol, mmol, g, mg, kg, mL of solution with molarity, litres of gas at STP or particles; leave it empty to see only the ratios.
5. For an experimental ratio, enter each substance and its amount. Formulas, names or a molar mass in g/mol all work; add the expected ratio to get the percent difference.
6. For two compounds, choose ratio or mass. Enter both masses for the molar ratio, or a target ratio to get the mass of B to weigh.
7. For DNA, enter the vector length and mass and each insert’s length and ratio. Presets give 3 : 1, 2 : 1, 5 : 1 and 1 : 1; add ng/µL to get volumes.
8. Press the button. Nothing is calculated before you press it, and changing any input clears the old answer.
9. Read the ratios, the steps and the charts. The Verified badge means mass is conserved and every amount matches the ratio.
10. Copy, share or batch. Copy the answer, share a link, download a report, or solve a whole worksheet on the Batch tab.

Excel handles mole ratio calculations in a few small tables: the coefficients of the balanced equation, a ratio column, a conversion row, an experimental-ratio table with MIN, and a DNA insert row. The sheets use the headline problems, so they must return 4.00 mol NH₃, Cu : Ag = 1 : 2 and 50.0 ng of insert, the same as the mole ratio calculator above.

9.1 The functions you need

9.2 Step by step

9.3 Awkward cases

• Fractional coefficients (H₂ + ½O₂): the ratios are the same; multiply all coefficients by 2 if you want whole numbers.
• Ratios near .5 or .33: add a column =E2*2 or =E2*3 before rounding with ROUND.
• Several inserts: one row per insert with the same vector cells, referenced with $.

9.4 Why your Excel answer might differ

9.5 Charting in Excel

1. Next to each substance, compute its moles for your amount: =$B$6*C2/$C$3.
2. Insert → Clustered Column; the bar heights follow the 1 : 3 : 2 ratio, as in chart 2 above.

9.6 Excel errors you will probably hit

This base R script stores the coefficients as a named vector, prints every mole ratio with combn, converts 6.00 mol of H₂ to ammonia, calculates an experimental Cu : Ag ratio from masses, checks the answers and saves a 300 dpi chart. For the headline problem it prints 4.00 mol and 68.1 g of NH₃, matching the mole ratio calculator on this page.

10.1 The complete script

R, base only, saves mole_ratio.png

# ============================================================
# Mole ratio calculator in R (base R only):
# all mole ratios from a balanced equation, a mole-to-mole conversion,
# and an experimental mole ratio from measured masses
# StatsUnlock - https://statsunlock.com/mole-ratio-calculator/
# ============================================================

# ---- 1. Balanced equation: N2 + 3 H2 -> 2 NH3 -------------------------------
coef <- c(N2 = 1, H2 = 3, NH3 = 2)
M    <- c(N2 = 28.014, H2 = 2.016, NH3 = 17.031)    # g/mol
gcd  <- function(a, b) if (b == 0) a else gcd(b, a %% b)

# ---- 2. Every mole ratio (all possible pairs) ------------------------------
pairs <- combn(names(coef), 2)
for (k in seq_len(ncol(pairs))) {
  a <- pairs[1, k]; b <- pairs[2, k]; g <- gcd(coef[a], coef[b])
  cat(sprintf("%s : %s = %d : %d\n", a, b, coef[a] / g, coef[b] / g))
}

# ---- 3. Mole-to-mole conversion: 6.00 mol H2 -> NH3 ------------------------
n_wanted <- 6.00 * coef["NH3"] / coef["H2"]          # mol x (2 / 3)
mass_wanted <- n_wanted * M["NH3"]
cat(sprintf("6.00 mol H2 x 2/3 = %.2f mol NH3 = %.1f g\n", n_wanted, mass_wanted))

# ---- 4. Experimental mole ratio: 1.27 g Cu gives 4.32 g Ag -----------------
moles <- c(Cu = 1.27 / 63.546, Ag = 4.32 / 107.870)
ratio <- moles / min(moles)
print(round(ratio, 3))
cat("Whole-number ratio Cu : Ag =", paste(round(ratio), collapse = " : "), "\n")

# ---- 5. Checks -------------------------------------------------------------
stopifnot(round(n_wanted, 2) == 4.00, round(mass_wanted, 1) == 68.1,
          all(round(ratio) == c(1, 2)), abs(ratio["Ag"] - 2.004) < 0.001)
cat("Verdict: Verified (all checks pass)\n")

# ---- 6. Figure: moles of every substance for 6.00 mol H2 -------------------
mol <- 6.00 * coef / coef["H2"]
png("mole_ratio.png", width = 2100, height = 1350, res = 300)
par(mar = c(4, 4.5, 3, 1))
bp <- barplot(mol, col = c("#2563eb", "#ea580c", "#16a34a"), ylab = "mol", ylim = c(0, 7),
              main = "N2 + 3 H2 -> 2 NH3: moles follow the 1 : 3 : 2 ratio")
text(bp, mol + 0.3, sprintf("%.2f mol", mol))
invisible(dev.off())
cat("Saved mole_ratio.png\n")

Output: N2 : H2 = 1 : 3, N2 : NH3 = 1 : 2, H2 : NH3 = 3 : 2, 6.00 mol H2 x 2/3 = 4.00 mol NH3 = 68.1 g, Whole-number ratio Cu : Ag = 1 : 2, Verdict: Verified.

10.2 R traps

• Index named vectors by name (coef["H2"]) so the ratio cannot be taken from the wrong substance.
• %% is the remainder operator, used in the gcd function; inside sprintf, a percent sign must also be written %%.
• Round only when printing; keep full precision for the ratio.

10.3 What each part does

10.4 The figure

The script saves mole_ratio.png at 2100 × 1350 pixels and 300 dpi: the moles of N₂, H₂ and NH₃ for 6.00 mol of H₂, following the 1 : 3 : 2 ratio.

This script does the same in plain Python: a dictionary of coefficients, every mole ratio with itertools.combinations, the mole-to-mole conversion, the experimental ratio, exact checks with fractions.Fraction and a 300 dpi chart. It is the same method the mole ratio calculator runs in your browser.

Install once: pip install matplotlib

11.1 The complete script

Python, saves mole_ratio.png

# ============================================================
# Mole ratio calculator in Python:
# all mole ratios from a balanced equation, a mole-to-mole conversion,
# and an experimental mole ratio from measured masses
# StatsUnlock - https://statsunlock.com/mole-ratio-calculator/
# pip install matplotlib
# ============================================================
from fractions import Fraction
from itertools import combinations
from math import gcd
import matplotlib
matplotlib.use("Agg")
import matplotlib.pyplot as plt

# ---- 1. Balanced equation: N2 + 3 H2 -> 2 NH3 -------------------------------
coef = {"N2": 1, "H2": 3, "NH3": 2}
M = {"N2": 28.014, "H2": 2.016, "NH3": 17.031}          # g/mol

# ---- 2. Every mole ratio (all possible pairs) ------------------------------
for a, b in combinations(coef, 2):
    g = gcd(coef[a], coef[b])
    print(f"{a} : {b} = {coef[a] // g} : {coef[b] // g}")

# ---- 3. Mole-to-mole conversion: 6.00 mol H2 -> NH3 ------------------------
given, amount, wanted = "H2", 6.00, "NH3"
n_wanted = amount * coef[wanted] / coef[given]             # mol x (2 / 3)
mass_wanted = n_wanted * M[wanted]
print(f"{amount:.2f} mol {given} x {coef[wanted]}/{coef[given]} = {n_wanted:.2f} mol {wanted} = {mass_wanted:.1f} g")

# ---- 4. Experimental mole ratio: 1.27 g Cu gives 4.32 g Ag -----------------
masses = {"Cu": 1.27, "Ag": 4.32}
molar = {"Cu": 63.546, "Ag": 107.870}
moles = {k: masses[k] / molar[k] for k in masses}
smallest = min(moles.values())
ratio = {k: v / smallest for k, v in moles.items()}
whole = {k: round(v) for k, v in ratio.items()}
print("Experimental:", {k: round(v, 3) for k, v in ratio.items()}, "->", whole)

# ---- 5. Checks ------------------------------------------------------------
assert Fraction(coef["NH3"], coef["H2"]) == Fraction(2, 3)
assert round(n_wanted, 2) == 4.00 and round(mass_wanted, 1) == 68.1
assert whole == {"Cu": 1, "Ag": 2} and abs(ratio["Ag"] - 2.004) < 0.001
print("Verdict: Verified (all checks pass)")

# ---- 6. Figure: moles of every substance for 6.00 mol H2 -------------------
names = list(coef)
mol = [amount * coef[s] / coef[given] for s in names]
fig, ax = plt.subplots(figsize=(7, 4.5))
ax.bar(names, mol, color=["#2563eb", "#ea580c", "#16a34a"])
for i, v in enumerate(mol):
    ax.text(i, v + 0.1, f"{v:.2f} mol", ha="center")
ax.set_ylabel("mol"); ax.set_title("N2 + 3 H2 -> 2 NH3: moles follow the 1 : 3 : 2 ratio")
fig.tight_layout(); fig.savefig("mole_ratio.png", dpi=300)
print("Saved mole_ratio.png")

Output: N2 : H2 = 1 : 3, 6.00 mol H2 x 2/3 = 4.00 mol NH3 = 68.1 g, Experimental: {'Cu': 1.0, 'Ag': 2.004} -> {'Cu': 1, 'Ag': 2}, Verdict: Verified.

11.2 Python traps

• Fraction(2, 3) keeps the ratio exact; 2 / 3 is a rounded float.
• round(1.5) gives 2 and round(2.5) gives 2 (round half to even): check values near .5 by multiplying instead.
• Use the same molar masses as your textbook if you want to match its third decimal.

11.3 Packages

pip install chempy balances equations with balance_stoichiometry, so the coefficients (and mole ratios) can come from formulas; molmass gives molar masses.

11.4 What each part does

11.5 The figure

The script saves mole_ratio.png at 300 dpi: the moles of each substance for 6.00 mol of H₂.

12.1 Mole ratios of common reactions

Every equation was balanced, and every ratio read off, by the same engine as the mole ratio calculator above.

12.2 Insert mass for common cloning setups

Insert mass = vector mass × (insert bp ÷ vector bp) × insert : vector molar ratio, with 50 ng of vector unless stated.

12.3 Mole ratio worksheet with answers

Twenty-five questions in three groups: mole ratios from equations, mole-to-mole and gram conversions, and experimental and DNA molar ratios. Every answer was checked by the mole ratio calculator engine. Cover the last column and try them first.

Eight examples run through the mole ratio calculator, from ammonia to an In-Fusion cloning reaction. Each figure is drawn from the computed numbers: one bar per substance (or DNA fragment) in moles, so the bar heights are the mole ratio.

This is the written method examiners expect, on the same problem as Sections 7, 9, 10 and 11: how many moles and grams of NH₃ form from 6.00 mol of H₂?

14.1 How to calculate mole ratio step by step

1. Balance the equation. N₂ + 3H₂ → 2NH₃.
2. Read the coefficients of the two substances: H₂ 3, NH₃ 2.
3. Write the mole ratio as a fraction, wanted over given: 2 mol NH₃ ÷ 3 mol H₂.
4. Multiply the moles you have: 6.00 mol H₂ × 2/3 = 4.00 mol NH₃.
5. Convert to grams if asked: 4.00 mol × 17.031 g/mol = 68.1 g.
6. Check: 6.00 ÷ 3 = 4.00 ÷ 2 = 2.00, the same extent of reaction.

14.2 How to calculate mole to mole ratio for every substance

For C₃H₈ + 5O₂ → 3CO₂ + 4H₂O there are six mole ratios: C₃H₈ : O₂ = 1 : 5, C₃H₈ : CO₂ = 1 : 3, C₃H₈ : H₂O = 1 : 4, O₂ : CO₂ = 5 : 3, O₂ : H₂O = 5 : 4 and CO₂ : H₂O = 3 : 4. With 1.000 mol of propane, multiply by each: 5.00 mol O₂, 3.00 mol CO₂, 4.00 mol H₂O.

14.3 How to calculate molar ratio from molecular weight (grams)

Divide each mass by its molecular weight first. 44.1 g of propane ÷ 44.097 g/mol = 1.000 mol, and 44.1 g of CO₂ would be 44.1 ÷ 44.009 = 1.002 mol: equal masses, almost equal moles here only because the molar masses happen to be close.

14.4 How to calculate experimental mole ratio

In the classic copper and silver nitrate experiment, 1.27 g of copper wire gives 4.32 g of silver. Moles: Cu 1.27 ÷ 63.546 = 0.01999 mol; Ag 4.32 ÷ 107.870 = 0.04005 mol. Divide by the smaller: 1 : 2.004, so Cu : Ag = 1 : 2, matching Cu + 2Ag⁺ → Cu²⁺ + 2Ag (a 0.2% difference). Load sample 6 in the mole ratio calculator to see every step.

14.5 How to calculate the molar ratio of two compounds

10.0 g of NaCl is 10.0 ÷ 58.440 = 0.1711 mol and 10.0 g of KCl is 10.0 ÷ 74.548 = 0.1341 mol, so NaCl : KCl = 1.28 : 1. To make a 1 : 2 mole ratio of glucose to sucrose with 5.00 g of glucose (180.156 g/mol): 0.02775 mol × 2 = 0.05551 mol of sucrose × 342.30 g/mol = 19.0 g.

14.6 How to calculate molar ratio for DNA cloning

For a ligation with T4 DNA ligase at 3 : 1 insert : vector, 50 ng of a 3000 bp vector and a 1000 bp insert: insert = 50 × (1000 ÷ 3000) × 3 = 50.0 ng. In moles, 50 ng ÷ (3000 × 617.96 + 36.04) g/mol = 26.97 fmol of vector and 80.9 fmol of insert. For In-Fusion (Takara recommends 2 : 1 for each insert) with 100 ng of a 5000 bp vector, a 1500 bp insert needs 100 × (1500 ÷ 5000) × 2 = 60.0 ng. The mole ratio calculator gives the same numbers, plus the volumes to pipette.

14.7 On a scientific calculator

On a Casio fx-991EX or fx-82MS, type the chain at once: 6.00 × 2 ÷ 3 = gives 4; then × 17.031 = gives 68.124.

Keep the unrounded answer (Ans) for the next step. Key names differ between models; check your manual.

14.8 Do it in the lab: the mole ratio of copper to silver

Example data. A ratio of 1 : 1 would point to copper(I), Cu + Ag⁺ → Cu⁺ + Ag; the measured 1 : 2.00 shows copper is oxidised to Cu²⁺.

14.9 How to calculate mole ratios: practice problems with answers

Ten practice problems, easy to hard. Open each one to see the answer.

14.10 Mistakes that lose marks

Research on stoichiometry finds that most errors come from the mole ratio and the conversion to moles, not the arithmetic (Gulacar et al., 2013; Mulford & Robinson, 2002).

• Using an unbalanced equation.
• Taking the ratio from subscripts instead of coefficients.
• Putting the ratio upside down (given over wanted).
• Multiplying grams by the mole ratio instead of moles.
• Rounding an experimental 1 : 1.5 to 1 : 2 instead of doubling it to 2 : 3.
• Using equal nanograms of insert and vector instead of a molar ratio.
• Rounding intermediate answers too early.

Four real examples

Decision tree

1. Do you have a chemical equation? Yes: equation mode, with or without an amount.
2. Did you measure masses of substances that reacted or formed? Yes: experimental mode.
3. Do you want the molar ratio of two compounds, or how much of one to weigh for a target ratio? Yes: two-compound mode.
4. Is it DNA? Yes: DNA mode with the vector and insert lengths.

Limitations. A mole ratio calculator gives stoichiometric ratios; it does not decide which reactant runs out first (use the limiting reagent) or how much product you will isolate (percent yield). Experimental ratios are rounded to whole numbers when every value is within 0.1 of one; a ratio that will not round is a sign of a measurement problem, not a new law of chemistry. DNA molar ratios recommended by vendors are starting points for optimisation, not guarantees.

What the answer is

A mole ratio is the ratio of coefficients in a balanced equation. For N₂ + 3H₂ → 2NH₃ it is 1 : 3 : 2, so 6.00 mol of H₂ gives 4.00 mol (68.1 g) of NH₃.

What it means chemically

It is the particle ratio of the reaction scaled up to moles, and the bridge between any two substances in every stoichiometric calculation.

Watch out for

Balance first, use coefficients not subscripts, convert grams to moles, put the wanted substance on top, and double an experimental 1 : 1.5 rather than rounding it.

Next steps

Practise with the worksheet in Section 12.3 and the ten problems in Section 14.9, then use the mole ratio calculator for your next stoichiometry problem or cloning reaction.

Mole ratios connect balancing, molar mass, stoichiometry and yield; these tools cover each step.

Peer-reviewed sources for the methods and data used in this mole ratio calculator: standard atomic weights, the definition of the mole, and research on how students learn stoichiometry and mole ratios. Cloning ratios follow the vendors’ published guidelines (New England Biolabs and Takara Bio).

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