Question

How many moles of alanine, C3H7NO2, are there in 159 g of alanine?How many moles of alanine, C3H7NO2, are there in 159 g of alanine?How many moles of alanine, C3H7NO2, are there in 159 g of alanine?​

Answer 1

To find the number of moles of Alanine, we first need to find its molar mass

Finding the Molar mass:

To our convenience, we are already given the chemical formula of Alanine

Chemical formula:  C₃H₇NO₂

Now, we will use this formula to find the molar mass of Alanine

to do that, we will replace the chemical symbols of elements with their respective molar masses and add them together

We know the following molar masses:

C is 12 g/mol

H is 1 g/mol

N is 14 g/mol

O is 16 g/mol

Now, we will replace the chemical symbols with their molar mass and will be multiplied by their values in subscript

C₃H₇NO₂

Molar mass = (12)*3  + (1)*7 + (14)*1 + (16)*2

Molar mass = 36 + 7 + 14 + 32

Molar mass = 89 grams/mol

Number of moles of Alanine in a 159 gram sample:

Number of moles = Given mass / Molar mass

Number of moles = 159 / 89

Number of Moles = 1.78 moles