How much heat does it take to convert 0.500 kg of ice at -20oC to steam at 250.oC?
Heat capacities: ice, 2.1 J g-1oC; liquid 4.2 J g-1 oC-1; steam 2.0 g-1 oC-1
Heat of fusion: 6.01 kJ/mol. Heat of vaporization: 40.7 kJ/mol.
In: Chemistry
Which of the following properties of a molecular compound can largely be explained by its intermolecular forces? Select as many as are applicable .Select one or more:
a) Vapor pressure
b) Covalent bond strengths
c) Solubility in various solvents
d) Enthalpy of combustion
e) Boiling point
f) Melting point
g) Hybridization of the atoms
In: Chemistry
Hyperthyroidism is a condition that occurs when the thyroid secretes an excess of hormones, leading to an increase in the metabolic rate of all the cells in the body. Hyperthyroidism increases the demand for glucose and for substrates for oxidative phosphorylation. Which metabolic pathways are active in the fasted state in the liver, muscle, and adipose tissue in order to meet this demand? Explain.
In: Chemistry
The enthalpy change for a chemical reaction is the sum of the energy consumed in breaking bonds and the energy released during bond formation. One way to determine the overall energy change for a chemical reaction is to apply Hess’s law to add together a group of reactions which can be arranged such that the chemical equations, when combined, give the overall equation we are trying to characterize.
part 1
Write a balanced chemical equation for the combustion of gaseous propane in gaseous oxygen to produce gaseous carbon dioxide and liquid water.
part 2
Combine the following equations to determine the enthalpy change
for the combustion of 1 mole of propane. Assume that solid carbon
is graphite.
Part 3
The average propane cylinder for a residential grill holds approximately 18 kg of propane. How much energy (in kJ) is released by the combustion of 18.50 kilograms of propane in sufficient oxygen?
In: Chemistry
Name five additives, besides flour, yeast, water, sugar and salt, found on a label of a loaf of bread. State the function of these additives
In: Chemistry
|
Weight of Unknown #4( in g) |
Volume of water (in mL) |
Unknown #4 solution (in g/L) |
|
0.118 |
50.00 |
2.36 |
|
0.127 |
50.00 |
2.54 |
|
0.112 |
50.00 |
2.24 |
Volume of NaOH used = Final concentration – Initial concentration
= 16.49 mL – 4.90 mL = 11.49mL NaOH= 0.01149 L NaOH
|
Exp. # |
Concentration of NaOH |
Initial volume of NaOH |
Final volume of NaOH |
Volume of NaOH used for titration |
|
1 |
0.1030M |
4.90mL |
16.49mL |
11.59mL |
|
2 |
0.1030M |
16.49mL |
26.01mL |
9.52mL |
|
3 |
0.1030M |
26.01mL |
35.09mL |
9.08mL |
a) Propose whether the unknown #4 is monoprotic or diprotic.
b) Propose the molar mass of the unknown #4.
c) show the calculation for the assumption for the monoprotic or diprotic.
In: Chemistry
Fe(III) forms a complex with thiocyanate, Fe(SCN)2+, that has a molar absorptivity of 7.00 x 103 at 580 nm. A 5.00 ml aliquot of a solution that contains 47.4 ppm Fe3+ is reacted with excess thiocyanate and diluted to 25 ml.
a) What fraction of 580 nm light is absorbed in a 1.00 cm pathlength cell by this solution?
Consider 5.00 ml of this solution diluted to a volume of 50ml
b) What fraction of 580 nm light is absorbed in a 1.00 cm pathlength cell by the diluted solution?
In: Chemistry
Calculate [OH−] for each solution.
A. pH = 2.52
B. pH = 8.09
C. pH = 13.58
In: Chemistry
Write the formulas and provide the associated name for each formula for the four acids that contain oxyanions of bromine.
In: Chemistry
Acetic acid and its conjugate base acetate can form an acid-base buffer. The pKa of acetic acid is 4.75. How much 10.0 M HNO3 must be added to 1.00 L of a buffer that is 0.0100 M acetic acid and 0.100 M sodium acetate to reduce the pH to 4.85 ?
In: Chemistry
*Please show how you got the calculations.
In a reactor scenario, 20.000 g Fe3O4 was reacted, at 1450 K, with NO having an initial pressure of 3.000 atm. At equilibrium, the mass of the solid-phase product (Fe2O3) was calculated to be 8.0742 g. 2Fe3O4(s) + 2NO(g) <=> 3Fe2O3(s) + N2O(g)
1. Calculate the mass of each gas-phase species at equilibrium.
2. Calculate the mass of Fe3O4 remaining at equilibrium from the mass of Fe2O3 calculated to exist at equilibrium.
3. Calculate the total mass of all species at equilibrium and prove that it equals the initial total mass of the reactants, to the .1 g place.
In: Chemistry
When electricity (the flow of electrons) is passed through a solution, it causes an oxidation-reduction (redox) reaction to occur. If the solution contains a metal cation such as Ag+, the flow of electrons will reduce the silver ion, causing solid silver to plate onto the electrode. The amount of metal plated depends on the number of electrons passed.
The total charge of a mole of electrons is 96,485 coulombs (C) and
1ampere(A)=1coulomb/second(C/s)
A) What mass of Cu(s) is electroplated by running 27.0 A of current through a Cu2+(aq) solution for 4.00 h?
B) How many minutes will it take to electroplate 34.1 g of gold by running 5.00 A of current through a solution of Au+(aq)?
In: Chemistry
AP CHEM question! Can you please follow these steps for each: 1.) net ionic equation, 2.) ice table, 3.) pH= pKa + log (CB/WA)
A 35.0 mL sample of 0.150 M acetic acid (HC2H3O2) is titrated
with 0.150 M NaOH solution. Calculate the pH after the following
volumes of base have been added:
A.) 0 mL
B.) 17.5 mL
C.) 34.5 mL
D.) 35.0 mL
E.) 35.5 mL
F.) 50.0 mL
In: Chemistry
For each of the reactions, calculate the mass (in grams) of the product formed when 3.75 g of the underlined reactant completely reacts. Assume that there is more than enough of the other reactant.
Ba(s)−−−−−+Cl2(g)→BaCl2(s)
CaO(s)−−−−−−+CO2(g)→CaCO3(s)
2Mg(s)−−−−−+O2(g)→2MgO(s)
In: Chemistry
In the Introduction to Equilibrium experiment, what kind of errors would occur? (need to write discussion)
In: Chemistry