Balancing Equations
___ N2 + ___ H2 -> ___ NH3
Balance this equation
1N2 + 3H2 -> 2NH3
Which of the following bonds does not form hydrogen bonds?
C-H
O-H
N-H
F-H
C-H
An aqueous solution of the salt Na2SO4 is combined with an aqueous solution of the salt (NH4)(C2H3O2). What precipitate is formed?
No precipitate is formed
If you have 6 mol of glucose, C6H12O6, the most important energy source in all organisms, how many moles of O atoms do you have?
36
How do the molecules in a liquid behave as the temperature of the liquid increases?
The average kinetic energy increases.
___ Na + ___ NaNO3 -> ___ Na2O + ___ N2
What is in front of Na2O?
6
Which of the following intermolecular forces will you observe in any molecule?
London dispersion forces
hydrogen bonding
dipole-dipole forces
covalent networks
London dispersion forces
Which ion forms compounds that are generally insoluble in water?
NH4+
NO3 -
PO43-
(C2H3O2)-
PO43-
N2 (g) + 3 H2 (g) → 2 NH3 (g).
If we start with 0.010 mol of H2 (g), we can produce how many moles of NH3 (g)?
0.0067 mol NH3 (g)
Which of the following would most likely be a gas at room temperature?
NaCl
C2H2
Na (s, metal)
C (diamond)
C2H2
___ H3PO4 + ___ KOH -> ___ K3PO4 + ___ H2O
What is in front of KOH?
3
Two different compounds have the same elemental composition, C3H8O. One has a low boiling point and the other a much higher boiling point. What attractive force must be present in one of these compounds that is not present in the other?
Hydrogen bonding
H2SO4 (aq) + 2KOH (aq) -> K2SO4 (aq) + 2 H2O (l)
What salt would be left if you evaporated the water?
K2SO4
When one mole of the salt Na2CO3 is combined with water, what are the resulting substance or substances in the water?
2 mol of Na+ (aq) + 1 mol of CO32- (aq)
Consider the balanced chemical equation:
SiCl4 (s) + 2 H2O (g) → SiO2 (s)+ 4 HCl (g).
How many grams of H2O will react completely with 5.000 g of SiCl4?
1.060 g
When the following chemical equation is balanced,
_ C4H10 + _O2 → _CO2 + H2O, the smallest integer coefficient in front of CO2 is
8
Pure NH3 boils at -33.3 °C and H2O boils at 100 °C. (The NH3 you buy commercially for cleaning is not pure. It is mixed with water.) Explain the difference in boiling points.
The intermolecular hydrogen bonding between NH3 molecules is weaker than that in H2O molecules because O is more electronegative than N.
Pb(NO3)2 (aq) + Na2SO4 (aq) -> PbSO4 (s) + 2 NaNO3 (aq)
What are the spectator ions?
Na+ and NO3-
N2 (g) + 3 H2 (g) → 2 NH3 (g).
If we start with 12.8 g of N2 (g), which of the following is true?
We require 1.37 mol H2 (g)
We can make 0.92 mol NH3 (g)
It is impossible to do the reaction because the stoichiometry requires 1 mole of N2 (g)
Both 1 and 2
Both 1 and 2
Which of the following is true considering soap?
The ion consists of a nonpolar tail made of C-H bonds and a polar COO- head group.
Owing to its polar head group, the laureate ion is soluble in water.
Two of the ions can combine with Ca2+ or Mg2+ ions to form a precipitate, otherwise known as “soap scum.”
All of the above.
All of the above.
When the following equation is balanced
_C6H12O6 (s) + _O2 (g) → _CO2 (g) + _H2O (g), what is the smallest integer coefficient in front of C6H12O6 (s)?
1
Which of the following would you expect to have the highest boiling point?
ethane, C2H6
carbon monoxide, CO
methyl alcohol, CH3OH
methyl fluoride, CH3F
methyl alcohol, CH3OH
An aqueous solution of Pb(NO3)2 is mixed with an aqueous solution of KI. What precipitate is formed?
PbI2
What is the molar mass (the mass of one formula unit) of calcium acetate, Ca(C2H3O2)2, which is used in dialysis treatments? Round to the 1s place.
158 g/mol
In the Haber process, 0.70 mol of NH3 (g) is produced from 0.35 mol N2 (g) and 1.05 mol H2 (g). What is the theoretical yield of the process in grams?
12 grams