To prevent brain damage, a standard procedure is to lower the body temperature of someone who has been resuscitated after suffering cardiac arrest. What is the physiochemical basis for this procedure?
In: Chemistry
The pH of an aqueous solution of 0.572 M caffeine (a weak base with the formula C8H10N4O2) is:
In: Chemistry
Two thousand (2,000) pigs in the growing-finishing stage (60 kg) are housed at a temperature (Ti) of 15 C. The indoor relative humidity (RHi) should not exceed 70%. The outdoor air conditions are To = -10 C and RHo = 50%. The UA value for the structure is 10,050 J/s.C. Will supplemental heat (Qsupp) be required for this structure, if so how much (J/s)?
In: Chemistry
At what point(s) during the oscillation of a spring that obey's Hooke's law is the force on the mass the greatest?
In: Chemistry
What is the difference between a reversible and irreversible process in chemistry?
In: Chemistry
Given these reactions,
X(s) + 1/2 O2(g) -----> XO(s) Delta H = -699.3 kJ/mol
XCO3(s) -------> XO(s) + CO2(g) Delta H = +328.3 kJ/mol
what is Delta Hrxn for this reaction?
X(s) + 1/2 O2(g) + CO2(g) -------> XCO3(s) Delta H = kJ/mol
In: Chemistry
Calculate the equilibrium constant for the reaction between Ni2+(aq) and Zn(s) under standard conditions at 25∘C.
In: Chemistry
4.
Which reactions are redox reactions?
Choose at least one answer.
| A. hydrochloric acid reacting with nickel metal to form hydrogen gas and aqueous nickel(II) chloride | ||
| B. sodium bromide reacting with chlorine to form sodium chloride and bromine | ||
| C. sodium hydroxide reacting with aluminum chloride to form solid aluminum hydroxide and sodium chloride | ||
| D. sodium hydroxide reacting with hydrochloric acid to form water and sodium chloride | ||
| E. sodium hydroxide reacting with potassium to form potassium hydroxide and sodium | ||
| F. acetic acid reacting with sodium bicarbonate to form carbon dioxide, water and sodium acetate |
In: Chemistry
When tert-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 45% tert-butyl chloride and 55% tert-butyl bromide is obtained. On the other hand, when n-butanol is placed in the presence of excess equimolar amounts of chloride and bromide ions in aqueous acid experimental data indicates 16% of n-butyl chloride and 84% n-butyl bromide is obtained. Now when n-butanol is placed in the presence of excess equimolar amounts of chloride ions and bromide ions in acid dimethyl sulfoxide the experimental data provides an 84% n-butyl chloride and 16% n-butyl bromide as the outcome.
1.) write balanced chemical equations for all three reactions (hint: account for mole ratios!).
2.) draw complete mechanisms for all three reactions.
3.) calculate the theoretical yield for the chlorides and bromides if each reaction was started with 5.55ml of the corresponding alcohol, using an aqueous acid media.
Sample: tert
Theoretical g of chloride
Theoretical g of bromide
Sample: n-
Theoretical g of chloride
Theoretical g of bromide
In: Chemistry
Carbonic acid, H2CO3, is a weak diprotic acid. In a 0.1 M solution of the acid, which of the following species is present in the largest amount?
|
H2CO3. |
||
|
H3O+ |
||
|
HCO3 |
In: Chemistry
A .053M solution of a weak base has a pH of 9.87. What is the Kb of this weak monprotic acid?
In: Chemistry
The formation constant* of [M(CN)6]4– is 2.50 × 1017, where M is a generic metal. A 0.130-mole quantity of M(NO3)2 is added to a liter of 1.150 M NaCN solution. What is the concentration of M2 ions at equilibrium?
In: Chemistry
1. Add 0.5 mL of 0.10 M NiCl2 solution to each of 7 test tubes using dropper provided. Label these tubes 1 through 7. 2. Add the following to the respective tubes containing the NiCl2 solution,
Tube 1: 5 drops of water (used here as a control experiment for dilution)
Tube 2: 1 mL of conc. HCl
Tube 3: 5 drops of conc. ammonia
Tube 4: 5 drops of dilute (5% v/v) ethylenediamine solution
Tube 5: 5 drops of 0.25 M C2O4 2- (oxalate) solution
Tube 6: 5 drops of 0.1 M SCN- (thiocyanate) solution
Tube 7: 5 drops of 0.1 M EDTA solution Mix each solution thoroughly and be sure to note the colour of each tube.
3. Check the stability of each complex by adding 3-5 drops of 1 M NaOH solution. Note any changes (e.g., formation of precipitate, colour change, etc.)
4. Add 0.5 mL of 0.10 M CuSO4 solution to each of 7 new test tubes labeled 8 through 14 using dropper provided. Repeat steps 2 and 3.
The “field strength” of a ligand describes how strong the coordination bond is, for a given metal and the ligand that is considered. The field strength is evaluated by considering how much it causes the d orbitals to split (DE), which of the ligands is strongest? Which is the weakest? Explain your choices in each case.
In: Chemistry
The balanced equation for the neutralization reaction of aqueous H2SO4 with aqueous KOH is shown.
H2SO4(aq)====>2H2O (l) +K2SO4(aq)
What volume of 0.370 M KOH is needed to react completely with 15.5 mL of 0.135 M H2SO4? Assume the reaction goes to completion.
In: Chemistry
Calculate the pH when 2.63 g of C6H5COONa is added to 41 mL of 0.50 M benzoic acid, C6H5COOH. Ignore any changes in volume. The Ka value for C6H5COOH is 6.5 x 10-5
In: Chemistry