Show:
Reactions and Stoichiometry
Electronic Structure and Periodicity
Thermochemistry
Bonding
Chemistry Pot-luck
100
A reaction that produces a gas is carried out in a sealed vessel on a balance. What happens to the mass the balance shows, as the reaction proceeds?
It does not change
100
How many unpaired electrons does a ground state N atom have?
3
100
What is the average kinetic energy per particle more commonly called?
Temperature
100

What type of bonding would you expect to exist in a sample of bronze?

Metallic substitutional bonding

100

Why does NH3(l) boil at −28°C, whereas PH3(l) boils at −126°C?

NH3 contains hydrogen bonds that require more energy to overcome than the dipole-dipole forces in PH3

200

Which of these is a weak acid? C6H12O6, H2SO4, HNO3, HF, HClO4

HF

200
Which of the subshells in the 3rd shell is destabilized the LEAST by inner electrons?
The 3s subshell
200
What happens to the enthalpy of a system during an endothermic process?
It increases
200
What is the missing word? Breaking bonds __________ energy
"requires" or "needs"
200

Apart from mercury, what is the only other element that is liquid at room temperature and atmospheric pressure?

Bromine

300
What is the formula of the precipitate formed when ammonium sulfate solution reacts with strontium nitrate solution?
SrSO4
300
Out of C, Si and P: which has the highest electronegativity?
C
300
What is the sign of "delta H of vaporization" and how does its magnitude compare to "delta H of fusion" for a typical substance?
The sign is positive (endothermic) and it is generally greater than "delta H of fusion"
300

Why is CO2 nonpolar but SO2 is polar?

The S has an extra lone pair which makes the shape bent.

300

Which form (allotrope) of oxygen is produced in lightening strikes?

Ozone (O3)

400
How many moles of oxygen gas are required to completely burn 4 moles of methanol (CH3OH)?
2CH3OH + 3O2 gives 2CO2 + 4H2O 6moles of O2 are required
400

Which of these elements has the lowest first ionization energy: Mg, Al, Si, P, Br, C, N ?

Al (dip after Mg)

400
How do you calculate the enthalpy change of a reaction, using the standard enthalpy change of formation of the reactants and products of the reaction?
Enthalpy change of reaction = sum of standard enthalpy change of formation of products - sum of standard enthalpy change of formation of reactants
400
Which of these species has an atom with an expanded octet? ozone, triiodide ion, selenium dichloride, arsenic trifluoride
triiodide ion
400

What color is liquid oxygen?

Blue

500
What piece of glassware is used to make up an exact 1.000M solution of NaCl(aq)?
Volumetric flask
500

What is the correct explanation for why a sulfide ion has a larger radius than a sulfur atom?

Increased electron-electron repulsion in the outer shell

500

A salt dissolves in water in a calorimeter and the forces formed are weaker than those broken. If the calorimeter does not insulate completely, how does the enthalpy change measured compare to the true enthalpy change for the dissolving? (give the sign of the enthalpy change and how the experimental value deviates from true)

The experimental enthalpy change is positive and smaller in magnitude than the true value

500
Which of these species displays resonance? phosphorus pentachloride, phosphate ion, tetraphosporus decoxide, carbon monoxide
phosphate ion
500

Where did Mr. Q study chemistry?

RU-N