Question

How many moles of O2 are needed to react with 2.35 mol of C2H2?

Answer 1

Answer : The number of moles of $O_2$ needed are 5.88 moles.

Solution : Given,

Moles of $C_2H_2$ = 2.35 mole

The balanced chemical reaction will be,

$2C_2H_2+5O_2\rightarrow 4CO_2+2H_2O$

From the balanced reaction we conclude that

As, 2 moles of $C_2H_2$ react with 5 moles of $O_2$

So, 2.35 moles of $C_2H_2$ react with $\frac{2.35}{2}\times 5=5.88$ moles of $O_2$

Therefore, the number of moles of $O_2$ needed are 5.88 moles.

Answer 2

2 C2H2 + 5 O2 --> 4 CO2 + 2 H2O

2.35 mol C2H2 - x mol O2
2 mol C2H2 - 5 mol O2

$x = \frac{2.35 \times 5}{2} = 5.875 \: mol$
answer: 5.875 mol