Reactivity 2.1 Review (Stoichiometry)

Everyday Conversions

Chemistry Conversions
g, mol, pariticles

Molar Mass or Mole Ratios

mass to mass stoichiometry

30 second Mrs. O questions

100

How many inches is 27.4 feet?

12 in = 1 ft 1 in = 2.54 cm

27.4 ft xx (12 Inches)/(1 ft) = 328.8 Inches

100

If you have 20 moles of lithium, how many atoms is that?

20 mol xx(6.02e23 "atoms")/(1 mol)= 1.204 e 25 "atoms"

1.204e25 = 1.204 x 10^25

100

What is the molar mass of caffeine?

C₈H₁₀N₄O₂

UNITS

194.19 g/mol

You need units!

100

4Fe + 3O₂ --> 2Fe₂O₃

How many grams of oxygen will react with 10 g iron?

10 g Fe xx(1 mol Fe)/(55.85 g Fe)xx(3 mol O2)/(4 mol Fe)xx(32 g O2)/(1 mol O2)=4.3gO2

100

What is Mrs. O's favorite color?

Teal

200

If your door is 678 centimeters (cm) long, how many feet is that?

How many inches is 27.4 feet?

12 in = 1 ft 1 in = 2.54 cm

678 cm xx (1 Inch)/(2.54 cm) xx (1 ft)/(12 Inches)= 22.2 ft

200

If you have 9.8x10²⁵formula units of Li₂O, how many moles is that?

9.8e25FU xx(1 mol)/(6.02e23 FU) = 162.8 mol

200

What is the mole ratio between Fe and Fe₂O₃?

2Fe₂O₃ + 3C --> 4Fe + 3CO₂

2 mol Fe₂O₃ = 4 mol Fe

200

CH₄ + 2O₂ --> CO₂ + 2H₂O

If 5 g of methane (CH₄) reacts with excess oxygen. How many grams of carbon dioxide should we expect?

200

How tall is Mrs. O?

5' 7''

300

How many dollars is 697 quarters?

1 dollar = 4 quarters

697 quarters xx (1 dollar)/(4 quarters) = 174.25 dollars

300

500 grams of CO₂ is how many moles?

500 g xx (1 mol CO2)/(44.01 g CO2)=11.36 mol

300

What is the molar mass of Ba(NO₃)₂?

Ba x 1 N x 2 O x 3

Use periodic table

261.34 g/mol

261 g Ba(NO₃)₂= 1 mol Ba(NO₃)₂

300

2I₂ + KIO₃ + 6HCl --> 5ICl + KCl +3H₂O

If 5.4 g of iodine reacts, what is the theoretical yield of ICl?

5.4 g I2 xx (1 mol I2)/(253.8 g I2) xx(5 mol ICl)/(2 mol I2) xx (162.35 gICl)/(1 mol ICl)= 8.6 g ICl

300

What color are Mrs. O's eyes?

blue

400

If Mrs. O watched 4.5 episodes of Spongebob on her treadmill, how many miles did she walk?

1 episode = 11 minutes

3 miles = 1 hr (her pace)

1 hr = 60 minutes

4.5 ep xx (11 min)/(1 ep)xx(1 hr)/(60 min)xx(3 mi)/(1 hr) = 2.475 mi

400

If you have 5.3 x 10²² atoms of Mg, how many grams is that?

5.3e22 "atoms" xx (1 mol)/(6.02e23 "atoms") xx (24.31 g)/(1 mol) = 2.1 g

400

What is the mole ratio needed if you know your starting amount of NaHCO₃ and need to predict your ending amount of Na₂SO₄?

2NaHCO₃(aq) + H₂SO₄(aq) --> Na₂SO₄(aq) + 2H₂O(l) + 2CO₂(g)

2 mol NaHCO₃ = 1 mol Na₂SO₄

400

2NaCl --> 2Na + Cl₂

You have 7 g of NaCl decomposing, what is the amount of Cl₂ you will produce?

7 g NaCl xx(1 mol NaCl)/(58.44g NaCL)xx(1 mol Cl2)/(2 mol NaCl)xx(70.91 g Cl2)/(1 mol Cl2)= 4.25g Cl2

4.25 g Cl₂

400

What is Mrs. O's favorite season?

Fall - When the air is crisp but not cold. Think pumpkin patch/apple orchard weather.

500

If you are 16.5 years old, how many seconds old are you?

1 yr = 365 days 1 day = 24 hours

1 hour = 60 minutes 1 minute = 60 seconds

16.5 yr xx (365 day)/(1 yr) xx (24 hr)/(1 day) xx (60 min)/(1 hr) xx (60 sec)/(1 min) = 5.2e8 sec

5.2e8 = 520344000 rounded

500

If you have 30 g of SO₂, how many molecules is that?

30 g xx(1 mol)/(64.07 g)xx(6.02e23 "molecules")/(1 mol)=2.82e23"molecules"

500

2Fe₂O₃ + 3C --> 4Fe + 3CO₂

If you have 68 moles Fe₂O₃, how many moles of Fe could you create?

68 mol Fe2O3 xx(4 mol Fe)/(2 mol Fe2O3) = 136 mol Fe

500

Pb(CH₃COO)₂ + H₂S --> PbS + 2CH₃COOH

If you create 27.3 g PbS, how many grams of CH₃COOH do you also create?

27.3 g PbS xx(1mol PbS)/(239.27 gPbS)xx(2 mol CH3COOH)/(1 mol PbS)xx(60.06gCH3COOH)/(1 mol CH3COOH)=13.7 g CH3COOH

500

Has Mrs. O been sky diving, and did she live?

Mrs. O has not and will never sky dive.