Facts about me
What's my major
biochem
Will a solution of Iron bromide oxidize solid magnesium metal? If so, what type of reaction is it? (Gas evolution, acid-base, redox etc.)
Yes, redox
What does stp stand for? (Double points if you can name the exact values each of them are...)
Standard temperature (0 degrees C or 273.15K) + pressure (1.00 atm)
What products (ions) will be present after dissolving magnesium hydroxide in water?
(no need to give me coefficients)
OH-, Mg2+
When is an element's oxidation number zero?
When it's in its natural state/when it's not combined with another element
Am I the oldest child, middle child, youngest, or an only child?
If I haven't told you this go based on vibes (be careful.. i will be offended.)
Oldest (I have 2 little sisters)
Assign oxidation numbers to Nitrogen and Oxygen in the Nitrite ion.
O = -2
N = +3
A giant flask containing 3.08L of CO2 gas is cooled from 95.0oC to 0.0oC. What is the final reading on the flask if the cooling occurs at a constant pressure?
We can use the simple gas law called Charles' Law here (PV=nRT solved for R is PV/nT, moles are constant before and after cooling, and pressure is constant (we are told this.) Therefore can use equation V1/T1 = V2/T2 because the only thing that is changing is volume and temp)
V1/T1 = V2/T2
T1 = 95 +273.15K = 368.15K
T2 = 0 = 273.15K
(3.08mL)/368.15K = V2/273.15K
V2 = 2.2852L
Write the balanced net ionic equation that results from the reaction of the 2 reactants below. Once ready, write your answer on the nearest whiteboard. First team to finish it on the board gets the points.
AgNO3 (aq) + CaCl2 (aq)->
Ag+(aq) + Cl-(aq) -> AgCl(s)
Under what conditions can one use the dilution equation, M1V1=M2V2?
When a dilution is happening (when no reaction is occurring)
Dr. May always says chemistry happens in ___
a. agony
b. Cowley Hall 156
c. moles
c. moles
Assign oxidation numbers to each element in H4P2O7
H = +1
P = +5
O = -2
Determine the mass of chlorine gas (Cl2) in a 10L tank at stp.
n = V / 22.4 = 10/22.4 = .446 mol (35.45 g/mol Cl2) =
31.7
Ni(s) + MnBr2 (aq) ->
Trick question- no reaction occurs! (Solid nickel can't "roll" down to Mn! (Nickel is beneath mn in the activity series))
When introducing the first example of a partial pressure problem, Dr. May asked the class if they had ever...
A. Pumped up a bike tire
B. Watched a balloon shrink at cold temps
C. Climbed Mount Everest
C. Climbed Mount Everest
Name one school to which I'm applying to pursue a Ph.D.
UChicago, Northwestern, Purdue, Caltech, UC Irvine, Rosalind Franklin, MCW
In the following redox reaction, which element is being oxidized and which is being reduced?
Fe2O3 (s) + 3CO (g) -> 2Fe (s) + 3CO2 (g)
(psst- this one is on your homework so if you haven't done it already here's some free points)
Ox = C (+2 in CO -> +4 in CO2)
Red = Fe (+3 in Fe2O3 -> 0 in Fe(s))
An can of whipped cream with a volume of 384ml is pressurized with 8.00g nitrous oxide (N2O) If the can is at 40oF, what is the pressure(in atm) in the can?
P = nRT/V
n = (8g/44.02g)= 0.1817mol
T = ((40oF)-32)/(9/5)= 4.4444oC = 277.59K
P= 0.1817(.08206)(277.59)/(0.384)
= 10.8 atm
Write a balanced net ionic equation for the reaction of sodium phosphate and calcium nitrate.
2PO43-(aq) + 3Ca2+(aq) -> Ca3(PO4)2 (s)
You’re given a graduated cylinder full of 1M hydro bromic acid. However, the reaction you need to perform requires .45M hydro bromic acid. How many mL of the 1M hydro bromic acid stock solution should you add to end up with 20mL of .45M hydro bromic acid?
9mL of stock solution
1M(V1) = .45M(20mL total)
V1 = 9
Free 500 pts for being brave!
Answer answer answer
Predict the products and state whether magnesium or lead is the element being reduced. No need to give me states of matter.
Magnesium metal is added to lead(II) acetate
(hint: lead is Pb)
Products are Pb(s) and Mg(C2H3O2)2 Lead is reduced.
Mg+Pb(C2H3O2)2→Mg(C2H3O2)2+Pb
An evacuated Erlenmeyer flask is filled with an unknown gas whose density is 1.2506 g/L at stp (0oC, 1.00 atm). What is the molar mass of the unknown gas? If you know the unknown gas occurs in a DIATOMIC state, what do you suspect the identity of the unknown gas to be?
*Vote on whether I should explain what diatomic means
molar mass = dRT/P
mm = 1.2504(.08206)(273.15)/1.00
mm = 28.027
Gas is diatomic, means mm of 1 of the atoms (the one that will be on the periodic table) will be HALF of what we just calculated.
28.027/2 = 14.01g/mol. The unknown gas is nitrogen gas (occurs naturally as N2)
HF (aq) + NaSO3 (aq) -> ?
NaF(aq) + H2O(l) + SO2 (g)
.545 g of FeCl3 reacts with 1.25g of sodium sulfide. If your actual yield is 0.283g of sodium sulfide, what is your percent yield?
TY = .349g Fe2S3
% Yield: 81%