Fun, not so fun idk
How do you round to the correct number of significant figures when multiplying/dividing two numbers?
Adding/subtracting?
*/÷ : the answer has the same number of sig figs as the original number with the fewest sig figs
+/- : The answer has the same number of sig figs as the number with the fewest DECIMAL places
Dihydrogen monoxide
H2O
If you have 5 mol H₂ and 2 mol N₂, what is the limiting reagent in the reaction below?
3 H₂(g) + N₂ (g) → 2 NH₃ (g)
H2
C3H8 + O2 → H2O + CO2
C3H8 + 5O2 → 4H2O + 3CO2
Calculate the moles of BCl3 that will be required to produce 945 grams of B2H6?
BCl₃(g) + LiAlH₄(s) → B₂H₆(g) + LiAlCl₄(s)
BALANCED equation:
4BCl₃(g) + 3LiAlH₄(s) → 2B₂H₆(g) + 3LiAlCl₄(s)
68.3 mols
Conventional Notation for:
Kilo, centi, milli and micro
1000, 0.01, 0.001, 0.000001
Ammonium sulfate
(NH4)2SO4
If 33.6 g of NO and 26.9 g of O₂ react together, what is the mass in grams of NO₂ that can be formed via the reaction below?
2 NO (g) + O₂ (g) → 2 NO₂ (g)
51.06 grams NO2
Li2Se (s) + SO2 (g)
SSe2 (g) + Li2O (s)
2Li2Se (s) + SO2 (g)
SSe2 (g) + 2Li2O (s)
Determine the quantity of nitrogen atoms in 15.0 grams of Pb(NO2)2
6.04 x 1022
When are trailing zeros significant?
Leading zeros?
(trailing) When there is a decimal anywhere in the number.
(leading) NEVER
Na2CO3
Sodium carbonate
In this reaction: Mg (s) + I₂ (s) → MgI₂ (s)
If 4.56 moles of Mg react with 5.98 moles of I₂, and 3.79 moles of MgI₂ form, what is the percent yield?
63.4%
AlBr3 + K2SO4 → KBr + Al2(SO4)3
2AlBr3 + 3K2SO4 → 6KBr + Al2(SO4)3
Consider the chemical equation:
H₂(g) + N₂(g) → NH₃(g)
If 46.8 g H₂ and 179.4 g N₂ are mixed to form NH₃, which of the following substances is the limiting reactant?
BALANCED equation:
3H₂(g) + N₂(g) → 2NH₃(g)
Limiting Reagent: Nitrogen (N2)
Give the formula (including charges) for the following polyatomic ions:
Ammonium, Acetate, Hydroxide, Chlorate, Nitrate
FeCl3
Iron (III) chloride
You have 4.3 mol Xe and 3.0 mol F₂, but when you carry out the reaction you end up with only 1.35 mol XeF₄. What is the percent yield of this experiment?
Xe(g) + 2 F₂ (g) → XeF₄ (g)
90%
HClO4 + P4O10→ H3PO4 + Cl2O7
12HClO4 + P4O10 → 4H3PO4 + 6Cl2O7
Mercury(II) nitrate is a compound formerly used to treat fur to make felt for hats. It can also cause a psychological illness, which is where the phrase 'mad as a hatter' originated. Mercury(II) nitrate is synthesized by the reaction of mercury metal with hot concentrated nitric acid:
Hg(l) + HNO₃(aq) → Hg(NO₃)₂ + H₂(g)
What mass in grams of mercury metal would be required to form 6.55 grams of mercury(II) nitrate?
BALANCED equation:
Hg(l) + 2 HNO₃(aq) → Hg(NO₃)₂ + H₂(g)
4.05 grams Hg
Give the formula (including charges) for the following polyatomic ions:
Permanganate, Hydronium, Carbonate, Bicarbonate, Dichromate, Phosphate, Sulfate
MnO4-, H3O+, CO32-, HCO3-, Cr2O72-, PO43-, SO42-
CoBr2
Cobalt (II) bromide
Calculate the theoretical yield in grams of AlI3 from the complete reaction of 18.3 grams of Al according to the following BALANCED equation:
2Al (s) + 3I2 (s) → 2AlI3 (s)
277 grams AlI3
FeS2 + O2 → Fe2O3 + SO2
4FeS2 + 11O2 → 2Fe2O3 + 8SO2
If 25.0 g of NH₃ and 45.0 g of O₂ react in the following reaction, what is the mass in grams of NO that will be formed?
NH₃ (g) + O₂ (g) → NO (g) + H₂O (g)
BALANCED equation:
4 NH₃ (g) + 5 O₂ (g) → 4 NO (g) + 6 H₂O (g)
Mass: 33.8 g NO