Question #f69cb

2 Answers
Nov 7, 2017

Answer: 42.58 g of #NH_3#

Explanation:

To solve this question, we need to know the number of moles equivalent to the 35 g of #N_2# using moles concept.

1. Convert 35 g of #N_2# into the number of mols:

Molar mass of #N_2# = 28.0134 g/mol

Therefore,

number of moles = #frac(35 g)(28.0134 "g/mol") = 1.246 mols approx 1.25 mols #

We have given the balanced chemical equation as:

#N_2 + 3H_2 rightarrow 2NH_3#

From above balanced chemical reaction, we get that:

1 mol of #N_2# produces 2 mols of #NH_3#.

Therefore,

1.25 mols of #N_2# produces 2.5 mols of #NH_3#.

2. Convert 2.5 mols of #NH_3# into g:

Molar mass of #NH_3# = 17.031 g/mol which means

1 mol of #NH_3# = 17.031 g of #NH_3#
2.5 mols of #NH_3# = 42.5775 g of #NH_3# #approx# 42.58 g of #NH_3#

Nov 7, 2017

#4.25grams#

Explanation:

For this first we have to calculate moles of #N_2# from which we can calculate moles of #NH_3#. And from moles of #NH_3#, we can easily calculate its mass.
So let's start:

Moles of #N_2 = ##(mass of N_2(grams))/ (molar mass of N_2)#

# = (35grams)/(28grampermol)## = 1.25mols#

Now we have to use balance chemical equation:

# N_2 + 3H_2 to 2NH_3#

As we can see;

#1mol# #N_2# form number of moles of #NH_3 = 2#

#1.25 mols# #N_2# will form number of moles of #NH_3#

#=# #(2molNH_3)/(1molN_2)##xx# #1.25molN_2#

# = 2.5 molsNH_3#

Mass of #NH_3 =# number of moles #xx# molar mass

# = 2.5 xx 17 = 42.5grams#

#Note:#
The coefficients of reactants and products in balance chemical equation represent number of moles. And if there is no coefficient with a molecule then it means that number of mole = 1.