How many moles are there in 80.0g of C2H5Cl? leave answer in significant figures.

please help and explain how to get the answer.

80.0/molar mass = ??. You should round to 3 s.f.

To find the number of moles in a given mass of a substance, you need to use the molar mass of the substance. The molar mass is the mass of one mole of a substance and is calculated by summing the atomic masses of all the atoms in the chemical formula. The atomic masses can be found on the periodic table.

Let's calculate the molar mass of C2H5Cl:
Carbon (C) has an atomic mass of approximately 12.01 g/mol.
Hydrogen (H) has an atomic mass of approximately 1.01 g/mol.
Chlorine (Cl) has an atomic mass of approximately 35.45 g/mol.

Molar mass of C2H5Cl:
(2 × 12.01 g/mol) + (5 × 1.01 g/mol) + 35.45 g/mol = 64.53 g/mol

To find the number of moles in 80.0 g of C2H5Cl, divide the given mass by the molar mass:

80.0 g / 64.53 g/mol = 1.24 mol

Therefore, there are 1.24 moles of C2H5Cl in 80.0 g of C2H5Cl.

To find the number of moles in a given mass of substance, you need to use the formula:

moles = mass / molar mass

Step 1: Determine the molar mass of C2H5Cl.
C = 12.01 g/mol
H = 1.01 g/mol (there are 5 hydrogen atoms)
Cl = 35.45 g/mol

Molar mass of C2H5Cl = (2 * 12.01) + (5 * 1.01) + 35.45 = 64.53 g/mol

Step 2: Substitute the given mass into the formula.
moles = 80.0 g / 64.53 g/mol

Step 3: Calculate the moles.
moles ≈ 1.24 mol

Remember, when doing calculations, it's important to carry extra decimal places during intermediate steps and only round at the end.

So, there are approximately 1.24 moles of C2H5Cl in 80.0 g, using the correct number of significant figures.