Question

For the reaction shown, calculate how many moles of NO2 form when each of the following completely reacts. 2N2O5(g)→4NO2(g)+O2(g) Part A 1.0 mol N2O5 Express your answer using two significant figures. nothing mol m o l Request Answer Part B 5.4 mol N2O5 Express your answer using two significant figures.

Answer 1

Answer:

For part A: The number of moles of $NO_2$ is 2.0 moles.

For part B: The number of moles of $NO_2$ is $1.1\times 10^1$ moles.

Explanation:

For the given chemical equation:

$2N_2O_5(g)\rightarrow 4NO_2(g)+O_2(g)$

• For Part A: When 1.0 mole of $N_2O_5$ is reacted

By Stoichiometry of the reaction:

2 moles of $N_2O_5$ produces 4 moles of $NO_2$

So, 1.0 moles of $N_2O_5$ will produce = $\frac{4}{2}\times 1.0=2.0moles$ of $NO_2$

Hence, the number of moles of $NO_2$ expressed in two significant figures are 2.0 moles.

• For Part B: When 5.4 moles of $N_2O_5$ is reacted

By Stoichiometry of the reaction:

2 moles of $N_2O_5$ produces 4 moles of $NO_2$

So, 5.4 moles of $N_2O_5$ will produce = $\frac{4}{2}\times 5.4=10.8moles$ of $NO_2$

To express it in two significant figures, we round this value of 10.8 mol to 11 mole and then express it in scientific notation.

Scientific notation is defined as the way of representing a number which have very large value or very small value and is written in the decimal form.

Hence, the number of moles of $NO_2$ expressed in two significant figures are $1.1\times 10^1$ moles.