Chemsoc 1/5 Jeopardy

winter things

100

this condensation of ice particles on dust in the air is a welcome treat for students (and teachers)

snow

200

This is the marker that plants most commonly use to know when to grow after winter.

amount of daylight/length of day/night

300

this shape is the base of a snowflake's crystalline structure.

hexagon

400

This is the reason why salt is used on the streets to prevent ice.

lowers the freezing point of water - freezing point depression

500

This unique property of liquid vs solid water was the basis for an explanation (now proven false) of how ice skating is possible.

ice is less dense than liquid water - believed pressure from skaters' blades melted water

thermo

100

this is the sign of delta G when a reaction is spontaneous.

negative

200

Delta G has this kind of mathematical relationship to K_eq.

logarithmic

300

You perform a reaction in which the sides of the beaker get colder as it progresses. What must be true in order for it to be spontaneous?

positive entropy (must also be high enough)

400

This halogen has the highest standard entropy.

chlorine

500

Which electron-involving step in the Born-Haber calculation of lattice energy of LiF from its elements is exothermic?

(hint: think about formation of ions)

electron affinity of F(g)

bonding

100

carbon can make this number of bonds

4

200

This is the halogen acid with the strongest bond.

HF

300

This metaphor, using a natural feature of Earth, is often used to describe the way electrons are spread in a metallic bond.

sea

400

This is the number of different carbon-oxygen distances in the carbonate ion.

1

500

This covalent network solid, more widely known as a common type of crystal, makes up ~60% of the Earth's crust by mass.

SiO₂, or quartz

reactions

100

what element is always involved in combustion?

oxygen

200

Write the reaction between acetic acid and sodium hydroxide.

CH₃COOH + NaOH -> CH₃COO^- + Na⁺ + H₂O

300

write the chemical equation that corresponds to the standard enthalpy change for formation of MgO (s)

Mg+ 1/2 O₂ -> MgO

400

This is the reaction that occurs when calcium carbonate is roasted.

makes CaO and CO₂

500

These are the three things that have to occur in order for a reaction to happen.

molecules must collide, must have enough energy, correct orientation

imfs

100

This IMF is present in any compound with electrons.

london dispersion forces

200

this tree-like phenomenon in hydrocarbons can make some isomers have lower boiling points than others.

branching

300

This is the reason why carbon tetrachloride has a higher boiling point than chloroform (CHCl₃)

LDFs

400

These are the two factors that determine the strength of IMFs in ionic solids.

radius and charge

500

This is the reason why H₂O has a higher boiling point than NH₃.

ratio of lone pairs to H