CHEM 1342

Solids

100

Strongest intermolecular force?

Ion-dipole force

200

Which has higher viscosity: HOCH₂CH₂OH or water(H₂O)?

HOCH₂CH₂OH (ethylene glycol) - 2 hydrogen bonding

300

Which has lower vapor pressure: CCl₄ or BF₃ or PF₅?

CCl₄ - has more mass (all are non polar)

400

Solids that is characterized by a distinct lack of order in the arrangement of atoms?

Amorphous

500

Element A atoms are located at all 8 corners of the cubic unit cell. Element B atoms are located at the center of all 6 faces of the unit cell. What is the empirical formula of this compound?

8 * 1/8 = 1 atom of A

6 * 1/2 = 3 atoms of B

Empirical formula - AB₃

Solutions

100

Formula of Molarity(M)?

M = (moles of solute) / liters of solution

200

By Henry's Law, as solubility doubles what has happened to pressure?

Pressure is also doubled, as k is a constant. 

300

Which is a strong electrolyte: C₆H₁₂O₆ or AgNO₃?

AgNO₃ as it will dissociate and give two particles in solution

400

The solubility changes with temperature for solids and gas? (increase or decrease)

Solids: increases

Gases: decreases

500

Approximate value of the van't Hoff factor for: K₂SO₄ and Al(NO₃)₃?

K₂SO₄: 3

Al(NO₃)₃: 4

Maths

100

Find Henry's law constant when partial pressure is 2.5 atm at 25°C and the concentration is 0.030 M?

S = kP

k = (S / P)

k = (0.030 M / 2.5 atm)

k = 0.012 M/atm

200

What's the heat removed from 10.0g of CCl₃F, from 50.0^oC to 23.8^oC? 

C_s(g) = 0.59 J/g.K

q = C_smAT

q = (0.59 J/g.K) (10.0g) (23.8K - 50.0K)

q = -154.58J

300

The thermal decomposition of a certain compound is a first-order reaction with a rate constant(k) of 2.31 x 10^-3s^-1 at 400^oC.

t_1/2 = ln(2)/k

t_1/2 = 0.693/ of 2.31 x 10^-3s^-1

= 300 s

400

When 10.0 g of glucose (molar mass = 180.16g/mol) is dissolved in 100.0g of pure water, what is the new freezing point of the solution? K_f = 1.86^oC.kg/mol

Delta T_f = (1.86^oC.kg/mol) (1) {(10.0g/180.16g/mol) / 0.100kg}

Delta T_f = 1.03^oC

New Freezing Point = 0.00^oC - 1.03^oC = -1.03^oC

500

The radioactive isotope Iodine-131 has a half-life of 8.0 days. How long does it take for 75.0% of a sample of Iodine-131 to decay? (first order kinetics)

k = ln(2) / t_1/2 = 0.0866 day^-1

ln[A]_f = -kt + ln[A]_o

t = (ln(1-0.75) - ln(1)) / -0.0866 day^-1

t = 16.0 days

Kinetics

100

What is the order of a reaction if it's rate constant is M^-5s^-1?

6

200

A substance that slows down or stops a chemical reaction by increasing the activation energy

Inhibitor

300

Rate =k[A][B]²

What happens to the rate if [B] is tripled?

9x

400

Reaction rates are smaller than collision rates. Why?

As they need to cross the threshold energy and have correct orientation

500

Integrated Rate Law for second order reaction? 

1/[A]_t = kt + 1/[A]₀

Nuclear

100

High energy photon

Gamma Ray

200

Which requires more energy: Nuclear fission or Nuclear fusion?

Nuclear fusion(too much energy to push proton together)

300

Beta decay is the emission of? 

beta particle (electron or positron)

400

What type of radiation cannot penetrate a paper? 

Alpha particle

500

What is subcritical mass?

In a nuclear fission, the reaction fades away as there isn't enough amount of neutron.