Number of grams of bromine that wikll completely react with 5.0 g of pent -1- ene is ________ ` xx 10^(-2)` g . (Atomic mass of Br = 80 g/mol )

Explanation

To solve the problem of how many grams of bromine will completely react with 5.0 g of pent-1-ene, we can follow these steps:

### Step 1: Determine the Molar Mass of Pent-1-ene
Pent-1-ene (C5H10) has the following atomic masses:
- Carbon (C): 12 g/mol
- Hydrogen (H): 1 g/mol

Calculating the molar mass:
\[ \text{Molar mass of pent-1-ene} = (5 \times 12) + (10 \times 1) = 60 + 10 = 70 \text{ g/mol} \]

### Step 2: Calculate the Moles of Pent-1-ene
Using the mass of pent-1-ene given (5.0 g), we can find the number of moles:
\[ \text{Moles of pent-1-ene} = \frac{\text{mass}}{\text{molar mass}} = \frac{5.0 \text{ g}}{70 \text{ g/mol}} = 0.0714 \text{ mol} \]

### Step 3: Determine the Stoichiometry of the Reaction
The reaction between pent-1-ene and bromine (Br2) is a 1:1 reaction. This means that 1 mole of pent-1-ene reacts with 1 mole of bromine.

### Step 4: Calculate the Moles of Bromine Required
Since the reaction is 1:1, the moles of bromine required will be the same as the moles of pent-1-ene:
\[ \text{Moles of bromine} = 0.0714 \text{ mol} \]

### Step 5: Calculate the Mass of Bromine Required
Now, we need to calculate the mass of bromine using its molar mass. The molar mass of bromine (Br) is 80 g/mol.
\[ \text{Mass of bromine} = \text{moles} \times \text{molar mass} = 0.0714 \text{ mol} \times 80 \text{ g/mol} = 5.714 \text{ g} \]

### Step 6: Convert to the Required Format
The problem asks for the answer in the format of \( xx \times 10^{-2} \) g. Therefore, we convert 5.714 g:
\[ 5.714 \text{ g} = 571.4 \times 10^{-2} \text{ g} \]

### Final Answer
The number of grams of bromine that will completely react with 5.0 g of pent-1-ene is:
\[ \boxed{571.4} \]