General Stoich A (Study Guide Review)

Balancing Equations

100

In the balanced equation:

6 KCl + 1 Mg₃N₂ --> 2 K₃N + 3 MgCl₂

How many moles do you have of each compound?

6 moles of KCl

1 mol of Mg₃N₂

2 moles of K₃N

3 moles of MgCl₂

200

In the balanced equation:

1 CaF₂ + 2 K --> 2 KF + 1 Ca

How many moles do you have of each compound?

1 mole of CaF₂

2 moles of K

2 moles of KF

1 mole of Ca

300

Balance this equation.

__AlCl₃ + __Na₃N ---> __AlN + __NaCl

1, 1, 1, 3

400

Balance this equation. 

__MgCl₂ + __Na₃B ---> __Mg₃B₂ + __NaCl

Then determine how many moles NaCl has?

3, 2, 1, 6

NaCl has 6 moles

500

Balance this equation.

__NaO + __N₂ ----> __Na₃N + __O₂

Then determine how many moles for each compound.

6 moles of NaO

1 mole of N₂

2 moles of Na₃N

3 moles of O₂

Molar Mass

100

What is the molar mass of K?

What is the molar mass of Ca?

39 g/mol

40 g/mol

200

What is the molar mass of KCl?

74 g/mol

300

What is the molar mass of Mg₃N₂?

What is the molar mass of K₃N?

102 g/mol

131 g/mol

400

What is the molar mass of MgCl₂?

What is the molar mass of CaF₂?

What is the molar mass of KF?

94 g/mol

78 g/mol

58 g/mol

500

How do we determine the molar mass of an element? 

How do we determine the molar mass of a compound? 

The atomic mass on the periodic table.

Use the atomic mass for each element in the compound, then multiply that by how many there are. Repeat for the other elements in the compound. Add them all together. 

Moles --> Grams & Grams --> Moles

100

If you have 2 moles of K, how many grams is this?

78 grams

200

If you have 2 moles of KF, how many grams is this?

116 grams

300

If you have 6 moles of KCl, how many grams is this?

444 grams

400

If you have 2 moles of K₃N, how many grams is this?

If you have 3 moles of MgCl₂, how many grams is this?

262 grams

282 grams

500

If you have 3060 grams of Al₂O₃, how many moles is this?

30 moles

Moles --> Atoms & Atoms --> Moles

100

If you have 1 mole of any element, how many atoms are there?

6.022 x 10²³ atoms

200

What is Avogardo's number? What does this number tell us?

6.022 x 10²³ and this is how many atoms/molecules/formula units (particles) are in 1 mole.

300

If you have 2 moles of K₃N, how many atoms are there? Round 2 places behind the decimal.

1.20 x 10²⁴ atoms

400

If you have 3 moles of MgCl₂, how many atoms are there? Round 2 places behind the decimal.

1.81 x 10²⁴ atoms

500

If you have 6 moles of KCl, how many atoms are there? Round 2 places behind the decimal.

3.61 x 10²⁴ atoms

Grams-->Moles-->Atoms &Atoms -->Moles--> Grams

100

What is a mole?

A unit used in Chemistry to measure large quantities of small items.

200

How many atoms are in 1 gram of Hydrogen (H)? Round your answer to 3 places behind the decimal.

6.022 x 10²³ atoms

300

Convert 56 grams of KF into atoms. Round your answer to 2 places behind the decimal.

5.81 x 10²³ atoms

400

Convert 279.45 grams of MgCl₂ into atoms. Round your answer to 2 places behind the decimal.

1.79 x 10²⁴ atoms

500

If you have (4.22 x 10²⁵) atoms of Na₂S, how many grams is that? Round your answer to two places behind the decimal.

5465.96 grams