Describe clearly how you would apply the concepts of pH control of natural waters and redox chemistry to precipitate or remove dissolved metals from acid mine water. Explain how pH and redox potential can be manipulated to remove different metals from solution. The metals may include: iron, copper, lead, zinc, arsenic, chromium
In: Chemistry
what period three element has the following ionization
energies? (all in kj/mol)
IE1=1012, IE2=1900, IE3=2910, IE4=4960, IE5=6270, IE6=22,200
In: Chemistry
explain whether it is possible to determine the approximate concentration if a solution of that sample has an absorbance of 0.62
In: Chemistry
An aqueous solution is made by dissolving 21.2 grams of ammonium phosphate in 323 grams of water.
The molality of ammonium phosphate in the solution
is ? m.
In the laboratory you are asked to make a 0.150
m potassium sulfide solution using
15.7 grams of potassium
sulfide.
How much water should you add?
grams
If 20.9 grams of an aqueous solution of
ammonium phosphate,
(NH4)3PO4,
contains 3.33 grams of ammonium
phosphate, what is the percentage by mass of
ammonium phosphate in the solution?
% (NH4)3PO4
How many grams of KF are there in
195 grams of an aqueous solution that is
10.8 % by weight KF.
g KF
In: Chemistry
Using the equation: 2 NO + O2 à 2 NO2
Determine the limiting reactant if given 1.0 mol NO and 1.0 mol O2
Determine the limiting reactant if given 4.2 mol NO and 2.0 mol O2
Determine the limiting reactant if given 10.0 grams NO and 10.0 grams O2
Identify the species that is oxidized and the species that is reduced in each of the reactions below:
Fe + Cu2+ à Fe2+ + Cu
Mg + Fe2+ à Mg2+ + Fe
In: Chemistry
The half life of 14C is 5730 years. What fraction of the 14C nuclei in a sample are left after 8140 years?
In: Chemistry
You are studying the reaction of iodine with a ketone to produce iodoketone with the following equation:
I2 + ketone → iodoketone + H+ + I-
Data for initial rates and concentrations are given in the table below:
-d[I2]/dt [I2] [ketone] [H+]
mol-1 L s-1 M M M
7 x 10-5 5 x 10-4 0.2 1.0 x 10-2
7 x 10-5 3 x 10-4 0.2 1.0 x 10-2
1.7 x 10-5 5 x 10-4 0.5 1.0 x 10-2
5.4 x 10-5 5 x 10-4 0.5 3.2 x 10-2
| A.
0, 1, 0 |
|
| B.0, 1, 1 | |
| C.1, 1, 1 | |
| D.1, 2, 0 |
Calculate the average rate coefficient in te above question.
| A.0.003 | |
| B.0.013 | |
| C.0.025 | |
| D.0.034 |
In: Chemistry
A hot lump of 43.0 g of iron at an initial temperature of 62.6 °C is placed in 50.0 mL of H2O initially at 25.0 °C and allowed to reach thermal equilibrium. What is the final temperature of the iron and water given that the specific heat of iron is 0.449 J/(g·°C)? Assume no heat is lost to surroundings.
In: Chemistry
Urea (CH4N2O) is a common fertilizer that can be synthesized by the reaction of ammonia (NH3) with carbon dioxide as follows: 2NH3(aq)+CO2(aq)→CH4N2O(aq)+H2O(l) In an industrial synthesis of urea, a chemist combines 120.6 kg of ammonia with 211.4 kg of carbon dioxide and obtains 181.4 kg of urea.
Part A) Determine the limiting reactant.
Part B)Determine the theoretical yield of urea.
Part C) Determine the percent yield for the reaction.
In: Chemistry
A silver block, initially at 55.4 ∘C, is submerged into 100.0 g of water at 24.0 ∘C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 27.8 ∘C. What is the mass of the silver block? Express your answer to two significant figures and include the appropriate units.
In: Chemistry
1.a) If ΔE > 0 then energy is being absorbed by the system.
True
False
1.b) If ΔEsystem is positive then ΔEsurrounding must be:
|
negative |
||
|
none of these |
||
|
positive |
||
|
zero 1.c) Consider the following chemical equation and calculate how much heat is released when 77.90 grams of C2H6 reacts.
1.d) A 27.4 g cube of copper initially at 74.6 ºC is submerged into a cup filled with 121.4 grams of water at 13.6 ºC. Determine the final temperature of both substances at thermal equilibrium. HINTS: Specific heat of copper = 0.385 J/g × ºC Specific heat of water = 4.184 J/g × ºC - your answer should contain four significant figures. 1.e) Calculate the heat (in kJ) associated if 0.0107 kg of
CH4 was used for the reaction: |
In: Chemistry
Iron(III) oxide reacts with carbon monoxide according to the
equation:
Fe2O3(s)+3CO(g)→2Fe(s)+3CO2(g)
A reaction mixture initially contains 22.90 g Fe2O3 and 15.78 g
CO.
Once the reaction has occurred as completely as possible, what mass (in g) of the excess reactant is left?
In: Chemistry
The steroid hormone estriol contains only C, H, and O; combustion analysis of a 3.47 mg sample yields 9.53 mgCO2 and 2.60 mgH2O. On dissolving 7.55 mg of estriol in 0.500 g of camphor, the melting point of camphor is depressed by 1.97 ∘C. [For camphor, Kf = 37.7 (∘C⋅kg)/mol.]
i. What is the molecular weight of estriol?
ii. what is the probable formula?
2) The number of moles of ions in 30.0 mL of 3.00 M Na2SO4 is ________ moles.
In: Chemistry
The question I have is what are the balanced equations and net ionic equations for the four following scenarios.
1. Dissolving solid NaOH in water
2. Neutralization reaction of NaOH (aq) with 1.00 M HCl mass of cup and NaOH soultion
3. Neutrlization reaction of solid NaOH with 1.00 HCl
4. Neutralization reaction of NaOH (aq) with 1.00 M acetic acid
In: Chemistry
briefly explain on a fundamental chemical basis what effect adding charges has on the polymer chain and how this relates to polarons and charge transport within the organic material. Then describe three different methods or devices through which charge carriers are added to an OSC, the main purpose or function of each
In: Chemistry