For the reaction 2Na + Cl2--> 2NaCl , how many grams of Cl2 are required to react completely with 4.00 g Na?
a
71.6 g
b
6.09 g
c
3.54 g
d
21.1 g
how many moles in 4g of Na?
You will use half that many moles of Cl2.
Now convert that back to grams.
To determine the amount of Cl2 required to react completely with 4.00 g of Na, we first need to calculate the molar mass of Na and Cl2.
The molar mass of Na is 22.99 g/mol.
The molar mass of Cl2 is 35.45 g/mol (since Cl2 is a diatomic molecule).
Next, we can convert the given mass of Na into moles by dividing it by the molar mass of Na:
4.00 g Na / 22.99 g/mol Na = 0.174 mol Na
According to the balanced equation, 2 moles of Na react with 1 mole of Cl2. Therefore, the number of moles of Cl2 required can be calculated by multiplying the moles of Na by the ratio of Cl2 to Na in the balanced equation:
0.174 mol Na * (1 mol Cl2 / 2 mol Na) = 0.087 mol Cl2
Finally, we can convert the moles of Cl2 into grams by multiplying it by the molar mass of Cl2:
0.087 mol Cl2 * 35.45 g/mol Cl2 = 3.08 g Cl2
Therefore, the correct answer is option c) 3.54 g
To determine the number of grams of Cl2 required to react completely with 4.00 g of Na, we need to use stoichiometry.
Step 1: Write the balanced chemical equation for the reaction:
2Na + Cl2 -> 2NaCl
Step 2: Calculate the molar masses of Na and Cl2:
Molar mass of Na = 22.99 g/mol
Molar mass of Cl2 = 35.45 g/mol
Step 3: Convert grams of Na to moles of Na:
moles of Na = mass of Na / molar mass of Na
moles of Na = 4.00 g / 22.99 g/mol
moles of Na = 0.174 mol
Step 4: Use the stoichiometry of the balanced equation to determine the moles of Cl2 required:
From the balanced equation, we know that it requires 2 moles of Na for every 1 mole of Cl2.
moles of Cl2 = 0.174 mol Na * (1 mol Cl2 / 2 mol Na)
moles of Cl2 = 0.087 mol
Step 5: Convert moles of Cl2 to grams of Cl2:
mass of Cl2 = moles of Cl2 * molar mass of Cl2
mass of Cl2 = 0.087 mol * 35.45 g/mol
mass of Cl2 = 3.08 g
Therefore, the correct option is c) 3.54 g.