Question

Question #ea84f

Answer 1

`0.40` mol

Explanation:

You are given CuSO`""_4*5`H`""_2`O

Strategy: First find the weight of hydrated copper sulfate in grams per mole. Then, using that discovery as a conversion factor, find the number of moles in 100 grams.

Weight of hydrated copper sulfate

Step 1. Get the atomic mass and number of each atom per molecule

• Cu: 1 copper atom at 63.456 g/mol

• S: 1 sulfur atom at 32.06 g/mol

• O`""_4`: 4 oxygen atoms at 15.999 g/mol

• 5(H`""_2`): 10 hydrogen atoms at 1.008 g/mol

• 5(O): 5 oxygen atoms at 15.999 g/mol

Step 2. Multiply and add the terms of get the number of moles found in one gram.

`1xx63.456+1xx32.06+9xx15.999+10xx1.008=249.6` g/mol

The number of moles
Step 3. Multiply 100 grams times that result as a conversion factor.

`100" g"xx ((1" mol")/(249.6" g")) =0.40` mol

Because 1 mole is equivalent to `6.02xx10^23` objects, there are `2.41xx10^23` molecules in CuSO`""_4*5`H`""_2`O.