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Ballencing AsCl3 + NaBH4 = AsH3 + NaCl + BCl3

How do I balance
AsCl3 + NaBH4 = AsH3 + NaCl + BCl3

Seems a bit tricky but you can use a set of equations to solve even the most stubborn 'balance this equation' question:

1. Put letters in front of each species:

aAsCl3 + bNaBH4 --> cAsH3 + dNaCl + eBCl3

2. Create a table for each element in the species and write an algebraic equation:

As : 1a + 0b --> 1c + 0d + 0e
Cl : 3a + 0b --> 0c + 1d + 3e
Na : 0a + 1b --> 0c + 1d + 0e
B : 0a + 1b --> 0c + 0d + 1e
H : 0a + 4b --> 3c + 0d + 0e

3. Use the equations to find the numbers e.g.

For hydrogen 4b = 3c and since b and c have to be whole numbers we can say c = 4 and b = 3

Again it looks a lot harder than doing it 'one by one' but it will always lead you to the correct answer :yep: