General
What is Avagadro's number?
6.022 × 10²³
True or false: You need molar mass in a 1-step mole-to-mole problem.
False
How many moles of O2 will be formed from 1.65 moles of KClO3
2KClO3 -> 2KCl + 3O2
Show work
2.48 mol O2
What are the steps in a 2-step grams-to-moles problem?
→ Grams → moles → mole ratio.
What are the 3 steps in a mass-to-mass problem?
→ Grams → moles → mole ratio → grams.
You’re given moles of one substance and asked for moles of another. What do you use?
Mole ratio
How do you find the molar mass of B2 Br6
What is WRONG about this problem?
2KCIO3 -> 2KCl + 3O2
How many moles of KClO3 are needed to make 3.50 moles of KCl
3.50 m KCl | 2 |
1 | 2 | = 3.50 m
3.50 mol KCl | 2 mol KCIO3 |
1 | 2 mol KCl | = 3.50 mol KCIO3
You have 32.0 g of O₂. How many moles of O₂ is that?
1.0 mole
B2Br6 + 6HNO3 -> 2B(NO3)3 + 6HBr
how many grams of HBr are there if you have 3.0x1024 particles of B2Br6
2400g HBr
You’re given grams and asked for grams of another substance. What kind of problem is this?
A 3-step stoichiometry problem.
If a compound has a molar mass of 98.08 g/mol, how many grams is 1.5 moles?
147.12 grams (1.5 mol × 98.08 g/mol).
How many moles of CH4 are there in 40.233 grams of CH4
40.233 g CH4 | 1 mole CH4
1 | 16.043 g CH4 =2.5078mol CH4
3Hg(OH)2 + 2H3PO4 -> Hg3(PO4)2 + 6H2O
How many moles of H3PO4 are there if you have 4.123 moles of Hg(OH)2
2.749 mol H3PO4
2KClO3 -> 2KCl + 3O2
How many grams of O2 will form from 3.76 grams of KClO3
1.47 g O2
What’s the difference between mass and quantity in stoichiometry
Mass is measured in grams; quantity refers to moles.
What does molar mass allow you to convert between?
moles and grams
How many grams of CaCl2 are there in 1.048 mole of CaCl2?
116.3 g CaCl2
4NH3 + 5O2 -> 4NO + 6 H2O
How many particles of O2 are there if you have 5.61 mole NH3
4.22 x 1024 particles O2
B2Br6 + 6HNO3 -> 2B(NO3)3 + 6HBr
How many grams of HNO3 do you end up with if you start with 27.3g B(NO3)3
26.2 gHNO3
You're given particles of a reactant and asked for grams of product. What steps do you take?
→ Particles → moles → mole ratio → grams (mass).
You have 2.5 mol of N₂. How many moles of NH₃ can be made from N₂ + 3H₂ → 2NH₃?
→ 2.5 mol N₂ × (2 mol NH₃ / 1 mol N₂) = 5 mol NH₃.
How many particles of NO2 are there in 9.43 moles of NO2
5.68 x 1024 particles NO2
4NH3 + 5O2 -> 4NO + 6 H2O
How many moles of H2O are there if you have 95.5g NH3?
How many grams of NO are there if you have 2.76 mol H2O?
8.41 Mol H2O
55.2 grams NO
B2Br6 + 6HNO3 -> 2B(NO3)3 + 6HBr
How many particles of B2Br6 are there if you have 39.4 g of HNO3
6.27 x 1022 particles B2Br6