Question

How many gram of bromine react with 5 gram of pent-1-yne?

Answer 1

Answer : The grams of bromine react with 5 gram of pent-1-yne is, 23.33 g

Solution : Given,

Mass of pent-1-yne = 5 g

Molar mass of pent-1-yne = 68.12 g/mole

Molar mass of $Br_2$ = 159.808 g/mole

First we have to calculate the moles of pent-1-yne.

$\text{Moles of pent-1-yne}=\frac{\text{Mass of pent-1-yne}}{\text{Molar mass of pent-1-yne}}=\frac{5g}{68.12g/mole}=0.073moles$

Now we have to calculate the moles of bromine.

The balanced reaction will be,

$CH_3-CH_2-CH_2-C\equiv CH+2Br_2\rightarrow CH_3-CH_2-CH_2-C(Br_2)-CH(Br_2)$

From the balanced reaction we conclude that

1 mole of pent-1-yne react with 2 moles of bromine

0.073 moles of pent-1-yne react with $0.073\times 2=0.146$ moles of bromine

Now we have to calculate the mass of bromine.

$\text{Mass of bromine}=\text{Moles of bromine}\times \text{Molar mass of bromine}$

$\text{Mass of bromine}=(0.146moles)\times (159.808g/mole)=23.33g$

Therefore, the grams of bromine react with 5 gram of pent-1-yne is, 23.33 g