Unit 5 Recap

What is the definition of "molar mass" ?

• The number of particles there are in an element

• The mass of one mole of a substance

• The mass of one gram of a substance

• 
  

  $6.02\ x\ 10^{23}$

What is the molar mass of Nitrogen?

• 58.69 g/mol

• 7 g/mol

• 14 g/mol

• 28 g/mol

Check all options that equal 1 mol

• 40 g of Calcium

• 14 g of Nickel

• 32 g of Sulfur

• 12 g of Carbon

What is the definition of "molecular formula" ?

• The smallest whole number ratio of element atoms in a compound

• The actual ratio of element atoms on a compound

• A bunch of elements put together

• How many molecules there are in a substance

Determine the empirical formula:

Caproic acid is made of C, H and O. A 0.225 g sample contains 0.140 g carbon and 0.0235 g hydrogen

• $C_3H_5O$

• $C_6H_{12}O_2$

• $C_3H_6O$

• $C_6H_{12}O_6$

A chemist has 2.00 moles of iron atoms in a beaker, how many atoms does she have?

• $6.02\ \times\ 10^{23}\ atoms$

• $1.20\ \times\ 10^{23}\ atoms$

• 2.00 atoms

• $1.20\ \times\ 10^{24}\ atoms$

A compound composed of hydrogen and oxygen is found to contain 0.59 g of hydrogen and 9.40 g of oxygen. The molar mass of this compound is 34.0 g/mol.

Find the empirical formula.

• $H_2O_2$
  

• $HO$
  

• $H_2O$

• $HO_2$

How many sig figs are in 0.20190

• 3

• 4

• 5

• 6

What is the percent composition of Tin (Sn) in

 $SnO_2$  ?

• 33.3%

• 78.8%

• 21.2%

• 50.0%

Calculate the molar mass of acetic acid or

 $CH_3COOH$  

• 60.1 g/mol

• 60.1 mol

• 58.1 g/mol

• 58.1 mol