Chapter 8, Problem 8.1KSP

Calculate the mass of water produced in the previous example, (a) 21.02 g (b) 10.51 g (c) 11.61 g (d) 11.75 g (e) 5.400 g

Interpretation Introduction

Interpretation:

The mass of water produced in the key skill example should be identified from the given option.

Concept introduction:

• Mole ratios between the reactants and products of a reaction are depends upon the coefficients of respective reactant in a balanced chemical equation.
• Balanced chemical equation of a reaction is written according to law of conservation of mass.
• Number of grams of a substance from its number of moles is,

• $\text{Number of moles}\text{×}\text{Molecular}\text{mass in grams}\text{=}\text{Number}\text{of}\text{grams}$

Answer to Problem 8.1KSP

Correct answer:

(b) $\text{10}\text{.51g}$

Explanation of Solution

Reason for correct option

To find: the mass of water produced in the given reaction.

The mass of water produced in the given reaction is $\text{10}\text{.51g}$.

Explanation:

The balanced equation of the given reaction is fond as,

${\text{N}}_{\text{2}}{\text{H}}_{\text{4}}\text{+}2{\text{N}}_2{\text{O}}_4\to 6\text{NO}\text{+}{\text{2H}}_{\text{2}}\text{O}$

The limiting reactant of the reaction is found that ${\text{N}}_2{\text{O}}_4$.

Then,

The mole ratio between ${\text{N}}_2{\text{O}}_4$ and ${\text{H}}_{\text{2}}\text{O}$ in the given reaction is 1:1.

The number of mole of ${\text{N}}_2{\text{O}}_4$ in the reaction is found as $\text{0}\text{.58335 mol}$.

Therefore,

The number of moles of ${\text{H}}_{\text{2}}\text{O}$ formed is $\text{1}\text{×}\text{0}\text{.58335 mol}\text{=}\text{0}\text{.58335 mol}$

Equation for Number of grams of a substance from its number of moles is,

$\text{Number of moles}\text{×}\text{Molecular}\text{mass in grams}\text{=}\text{Number}\text{of}\text{grams}$

Then,

The mass of ${\text{H}}_{\text{2}}\text{O}$ formed is,

$\text{0}\text{.58335}\text{×}\text{18}\text{.02g}\text{=}\text{10}\text{.51g}$

Hence the correct option for mass of ${\text{H}}_{\text{2}}\text{O}$ produced is option b.

Reasons for incorrect options:

Writes all the masses of ${\text{H}}_{\text{2}}\text{O}$ produced given in the options except option b.

(a) $\text{21}\text{.02g}$

(c) $\text{11}\text{.61g}$

(d) $\text{11}\text{.75g}$

(e) $\text{5}\text{.4g}$

Explanation:

The mass of ${\text{H}}_{\text{2}}\text{O}$ produced in the given reaction is found as $\text{10}\text{.51g}$.

So, this value of mass of ${\text{H}}_{\text{2}}\text{O}$ produced is not matching with any of the above given mass of ${\text{H}}_{\text{2}}\text{O}$ produced in remaining options.

Hence the incorrect options are a, c, d and e.

Conclusion

Conclusion

The correct option for the mass of ${\text{H}}_{\text{2}}\text{O}$ produced in the given reaction is identified from the given options. The mass of ${\text{H}}_{\text{2}}\text{O}$ produced is determined by using the data’s given for the reaction.