Question

PLEASE HELP!!

Given the following balanced reaction between hydrochloric acid and oxygen gas to produce water and chlorine gas, how many grams of chlorine gas, Cl2, are produced from 27.8 g of hydrochloric acid and excess oxygen? (To find the molar mass in the problem, use the periodic table and round the mass to the hundreds place for calculation.)

4HCI(aq) +O2 ->2CI2 (g)+ 2H2O (I),

Answer 1

Answer : The mass of chlorine gas produced are, 26.95 grams.

Explanation : Given,

Mass of HCl = 27.8 g

Molar mass of HCl = 36.46 g/mole

First we have to calculate the moles of hydrochloric acid.

`\text{Moles of HCl}=\frac{\text{Mass of HCl}}{\text{Molar mass of HCl}}=(27.8g)/(36.46g/mole)=0.76mole`

Now we have to calculate the moles of chlorine gas.

The given balanced chemical reaction is,

`4HCI(aq)+O_2\rightarrow 2CI_2(g)+2H_2O(I)`

From the given balanced chemical reaction, we conclude that

As, 4 moles of hydrochloric acid react to give 2 moles of chlorine gas

So, 0.76 moles of hydrochloric acid react to give
`(2)/(4)* 0.76=0.38` moles of chlorine gas

Now we have to calculate the mass of chlorine gas.

`\text{Mass of }Cl_2=\text{Moles of }Cl_2* \text{Molar mass of }Cl_2`

Molar mass of
`Cl_2` = 70.91 g/mole

`\text{Mass of }Cl_2=0.38mole* 70.91g/mole=26.95g`

Therefore, the mass of chlorine gas produced are, 26.95 grams.

Answer 2

number of moles of HCl =
`(mass (g))/(molar mass)`
=
`(27.8 g)/(36.45)` = 0.763 mole
From balanced equation:
4 moles of HCl give 2 moles Cl2
0.763 mole HCl give ?? mole Cl2
by cross multiplication :
= 0.38 mole Cl2
mass of Cl2 = moles x molar mass = 0.38 x 70.9 = 27 g