Question

1) What is the mass of 6.2 mol of K2CO3?

Answer 1

`\boxed {\boxed {\sf 856.8648 \ grams \ of \ K_2CO_3}}`

Step-by-step explanation:

To convert from moles to grams, we must find the molar mass.

1. Molar Mass

First, identify the elements in the compound. K₂CO₃ It has potassium, carbon, and oxygen. Find these elements and their masses on the Periodic Table.

• K: 39.098 g/mol
• C: 12.011 g/mol
• O: 15.999 g/mol

Note the subscript of 2 after K and 3 after O. We must multiply oxygen's molar mass by 2, then oxygen's by 3, and add carbon.

• 2(39.098 g/mol) + 3(15.999 g/mol) + 12.011 g/mol= 138.204 g/mol

2. Convert Moles to Grams

Use the molar mass as a fraction.

`\frac {138.204 \ g \ K_2CO_3}{1 \ mol \ K_23CO_3}`

Multiply by the given number of moles: 6.2

`6.2 \ mol \ K_2CO_3 *\frac {138.204 \ g \ K_2CO_3}{1 \ mol \ K_23CO_3}`

`6.2 *\frac {138.204 \ g \ K_2CO_3}{1 }`

`6.2 * {138.204 \ g \ K_2CO_3}`

`856.8648 \ g \ K_2CO_3`

There are 856.8648 grams of potassium carbonate in 6.2 moles.