Question

How many grams are in 68.2 molecules of br2?

Answer 1

Answer:68.2 molecules of bromine gas weigh's $1.812\times 10^{-20} g$

Explanation:

Number of $Br_2$ molecules = 68.2

Number of molecules = Moles of $Br_2$ × Avogadro number

$68.2=n\times 6.022\times 10^{23} mol^{-1}$

$n=1.1325\times 10^{-22} moles$

$n=\frac{\text{Mass of the}Br_2}{\text{Molar mass of}Br_2}$

Molar mass of the $Br_2$ gas:

$1.1325\times 10^{-22} moles\times 160 g/mol=1.812\times 10^{-20} g$

68.2 molecules of bromine gas weigh's $1.812\times 10^{-20} g$

Answer 2

In 68.2 molecules of Br2 there are $1.818 \times 10^{-20}g$.

To calculate the amount of grams it is necessary to know the value of the molar mass of bromine:

$Br_{2}$ = 160g/mol

Remembering that:

                                  $1 mol = 6\times10^{23}$ molecules

Thus, to find the mass of the number of molecules, it is enough to perform the following expression:

                                        $\frac{6\times10^{23}molecules}{68.2 molecules} = \frac{160g}{xg}$

                                           $x = 1.818 \times 10^{20} g$

So, In 68.2 molecules of Br2 there are $1.818 \times 10^{-20}g$

Learn more about mole calculation in: brainly.com/question/11915867