ACS Review

Supercalifragilisticexpialidocious

100

What is the balanced net ionic equation for the precipitation reaction of 2 H₃PO₄ (aq)+ 3 CaCl₂ (aq)→???

A. Ca²⁺ + PO₄^3- → Ca₃(PO₄)₂ (s)

B. 6 H⁺ + 6 Cl^- → 6 HCl (aq)

C. 6 H⁺ + 6 Cl^- + 2 PO₄^3- + 3 Ca²⁺  → 6 H⁺ + 6 Cl^- + Ca₃(PO₄)₂ (s)

D. 6 H⁺ + 6 Cl^- + 2 PO₄^3- + 3 Ca²⁺  → 6 H⁺ + 6 Cl^- + 3 Ca²⁺ + 2 PO₄^3-

A

net ionic only contains the reagents used to create something. In this case, H+ and Cl- are aqueous ions on both sides of the equation and are not included in the net equation

200

Trivia! 

What were uppercase and lowercase letters called before the advent of the printing press?

Majuscules and minuscules

300

Which set of quantum numbers is correct and consistent with n=4? 

A. l=3, m_l=-3, m_s = + ½ 

B. l=4, m_l=+2, m_s = - ½ 

C. l=2, m_l=+3, m_s = + ½ 

D. l=3, m_l=-3, m_s = + 1

A: correct

B: l= (n-1)

C: m_l cannot be greater than l

D: m_s cannot be 1, only ever + 1/2 or -1/2

400

The best Lewis structure of N2H2 shows 

A. A nitrogen-nitrogen triple bond. 

B. A nitrogen-nitrogen simple bond. 

C. Each nitrogen with one nonbonding electron pair. 

D. Each nitrogen with two nonbonding electron pairs.

C

I can't draw out the lewis structure, you're going to have to trust me :)

500

100 mL of F₂(g) is mixed at a constant pressure with 20 mL of Cl₂ (g) and it produced 40 mL of a compound of Cl and F. Find the formula of the compound produced.

A. ClF

B. ClF₅

C. Cl₂F

D. ClF₃

B

Laser

100

Which pair of particles has the same number of electrons?

 A. F^-, Mg²⁺ 

B. Ne, Ar 

C. Br^-, Se 

D. Al³⁺, P^3-

A

F typically has 9 electrons but has a negative charge, making the total number of electrons 10. Mg typically has 12 electrons, but has a 2+ charge, removing two electrons and making the total number of electrons 10

200

Trivia!

What is half of a byte called?

a nibble 

300

Which electron configuration is impossible?

A. 1s²2s²2p⁶3s²3p⁶3d⁵4s² 

B. 1s²2s²2p⁶2d² 

C. 1s²2s²2p⁶3s²3p⁶ 

D. 1s²2s²2p⁵3s¹

B

The d subshells begin at 3d. A 2d subshell does not exist

400

How many moles of Ba₃N₂ are necessary to react completely with 1.5 mol of water? 

Ba₃N₂+ 6 H₂O → 3 Ba(OH)₂+ 2 NH₃ 

A. 0.25 mol 

B. 1 mol 

C. 6 mol 

D. 9 mol

A

1.5 mol H₂O x (1 Ba₃N₂ mol /6 mol H₂O) = 0.25 mol

500

What is the change in energy that occurs when the electron in H moves from n=2 to n=4? Is it endo or exothermic? (R_H= 2.18 x 10-18 J)

A. 8.41 x 10^-19 J, exothermic

B. 8.41 x 10^-19 J, endothermic

C. 4.18 x 10^-19 J, exothermic

D. 4.18 x 10^-19 J, endothermic

D

Too much math and I can't upload pictures. Trust.

Globular

100

Which molecule is polar? 

A. CCl₄ 

B. CS₂ 

C. PH₃ 

D. PF₅

C

The lone pair on PH₃ causes asymmetry 

200

What is the energy of a photon with a wavelength of 656 nm? 

A. 3.03x10^-19J 

B. 3.03x10^-28J 

C. 4.35x10^-31J 

D. 4.35x10^-40J

A

E=hc/lamda 

656 nm = 6.56 x 10^-7 m

E= (6.626 x 10^-34)(3.00 x 10⁸)/ (6.56 x 10^-7)

300

When a cold block of aluminum at 0°C is placed in room temperature water at 21°C in an insulated cup, the water and the aluminum end up at a final temperature of 19°C. Assuming there was no heat loss to the surroundings, which statement best describes the energy exchanged in this process?

A. The block of aluminum lost the energy that the water gained. 

B. The block of aluminum gained the energy that the water lost. 

C. The block of aluminum gained less energy compared to the energy lost by the water. 

D. The block of aluminum gained more energy compared to the energy lost by the water.

B

Al temp 0°C -> 19°C

H₂O temp 21°C -> 19°C

Aluminum gains heat, water loses heat, closed system

400

100g of Cu and 100g of Fe are both at STP. If 500 J of heat is added to each of them, which ends up warmer? (s, Cu= 0.385/s, Fe= 0.444)

A. Cu

B. Fe

A

STP = 0°C, 1 atm 

q=ms(DeltaT) -> q/ms= (DeltaT) 

Cu: 500/ (100 x 0.385) = 12.99 

Fe: 500/ (100 x 0.444) = 11.26

500

What is the concentration of HNO₃ if 37.26 mL of this acid are required to titrate 25.00 mL of 0.113 M KOH to equivalence

A. 0.1690 M

B. 0.0512 M

C. 0.0379 M

D. 0.0758 M

D

Because the molar ratio is 1:1, we can use: M₁V₁=M₂V₂ -> M₂V₂/V₁=M₁

(25.00)(0.113)/37.26 = 0.0758 M

Pain

100

What is the oxidizing agent in this reaction? 

Pt²⁺(aq) + CH₃CH₂OH (aq) → CH₃CHO (aq) + Pt (s) + 2 H⁺(aq) 

A. Pt²⁺ (aq) 

B. Pt (s) 

C. H⁺(aq) 

D. CH₃CH₂OH (aq)

A

Pt has an oxidation state of +2 as a reagent but an oxidation state of 0 as a product. This means 2 electrons were GAINED (OIL RIG). Pt was reduced and is thus the oxidizing agent

200

What is the correct name for N₂O₅? 

A. Nitrogen (II) oxide 

B. Nitrogen (V) oxide 

C. Dinitrogen oxide 

D. Dinitrogen pentoxide

D

N₂O₅ is a molecular compound and uses prefixes. 

2= di

5= penta

ending of oxygen is changed to -ide

300

A 10 gram sample of which substance contains the greatest number of hydrogen atoms? 

A. 10 grams of CH₄ 

B. 10 grams of HCl 

C. 10 grams of H₂ 

D. 10 grams of PH₃

C

CH₄= 10g/ 16.019 g/mol = 0.624 mol CH₄ (4 mol H)= 2.497 mol H

HCl= 10g/ 36.461 g/mol = 0.274 mol HCl (1 mol H)= 0.274 mol H

H₂=10g/ 2.016 g/mol = 4.96 mol H₂ (2 mol H)= 9.92 mol H

PH₃= 10g/ 33.998 g/mol = 0.294 mol PH₃ (3 mol H)= 0.882 mol H

400

What are the four quantum numbers for the last electron of S

 A. 3, 1, -1, -1/2

B. 3, 2, -1, 1/2

C. 2, 1, -1, -1/2

D. 2, 2, 1, 1/2

A 

electron configuration: 3s²3p⁴

n=3, row 3 from top off PT

l= 1, p subshell (3 boxes)

m_l= -1 (last electron in -1 box)

m_s= -1/2 (last electron facing down)

500

What is the mass of all products present at the end of the reaction when 30 g of propane (C₃H₈) are mixed with 50 g of atmospheric Oxygen (O₂)

*NOTE! This is a combustion reaction, make sure your reaction is balanced!!

C₃H₈ + O₂ ---> ???

A. CO₂= 41.3 g, H₂O= 22.5 g

B. CO₂= 22.5 g, H₂O= 41.3 g

C. CO₂= 17.6 g, H₂O= 33.9 g

D. CO₂= 33.9 g, H₂O= 17.6 g

A

C₃H₈ + 5O₂ ---> 3CO₂ + 4H₂O 

Too much math: find limiting reagent, use limiting reagent to solve for CO₂ and H₂O individually

Chlorospingus

100

Trivia! 

Based on archeological evidence, what is the first condiment humans ever put on their food?

Mustard

200

Which element has the highest electronegativity?

A. Cs

B. O

C. I

D. Li

B

electronegativity trend= more electronegative up and to the right

300

What solution volume is needed to prepare a 0.110 M solution of MgSO₄ using 10.3 g of the compound? The molar mass of MgSO₄ is 120.366 g/mol.

A. 9.41x10^-3 L 

B. 0.778 L 

C. 1.11 L 

D. 93.6 L

B

10.3 g/ 120.366 g/mol = 0.08557 mol

M= n/V -> V= n/M

V = (0.08557)/0.110 M = 0.778 L

400

A 50 L rigid steel drum is at 25°C and it's pressure is 1.05 atm. What is the pressure in the drum if the temperature is increased to 85°C

A. 2.52 atm

B. 3.57 atm

C. 1.26 atm

D. 1.31 atm

C

P₁V₁/n₁T₁ = P₂V₂/n₂T₂ -> P₂ = P₁(T₂/T₁)

n and P cancel because they are constant on both sides of the equation

change °C to K

P₂ = 1.05 (358/298) = 1.26 atm

500

An organic compound contains only carbon, hydrogen, nitrogen, and oxygen. It is 61.71% C, 4.03% H, 16.00% N by mass. What is it's empirical formula?

A. C₅H₄NO

B. C₉H₇N₂O₂

C. C₁₀H₈N₂O

D. C₁₁H₈NO₂

B

Find moles of each =, divide by the smallest to get integers. Because some are 0.5, multiply by 2