In: Chemistry
Put the terms in the appropriate blanks.
What is the difference between a 10% (v/v) methanol (CH3OH) solution and a 10% (m/m) methanol solution?
A 10% (v/v) methanol solution can be made by adding _________ of methanol to _________ of water, while a 10% (m/m) methanol solution can be made by adding _________ of methanol _________ of water.
a. 10 mL
b. 90 mL
c. 90 g
d. 100 g
e. 100 mL
f. 10 g
How do temperature and pressure affect the solubility of solids and gases in water?
An increase in temperature usually __________ the solubility of solids and ________ the solubility of gases in water. An increase in pressure of a gas above a liquid _________ the solubility of a gas within that solution and _________ the solubility of solids.
a. increases
b. decreases
c. has no effect on
Describe the formation of an aqueous LiBr solution, when solid LiBr dissolves in water.
The _________ at the surface of the solid are pulled into solution by the _________ water molecules, where the ________ process surrounds
In: Chemistry
1. Which chemical is formed upon the addition of HCl to methyl orange? Name (not IUPAC) and draw it.
2. Which chemical is formed upon the addition of NaOH to methyl orange? Name (not IUPAC) and draw it. Explain how you know.
3. Which chemical is formed upon the addition of HCl to phenolphthalein? Name (not IUPAC) and draw it.
4. Which chemical is formed upon the addition of NaOH to phenolphthalein? Name (not IUPAC) and draw it. Explain how you know.
In: Chemistry
What are the mole fraction (X) and molality (m) of ethanol (C2H5OH) in an aqueous solution that is 45.0% ethanol by volume? The density of water is 1.00 g/mL and that of ethanol is 0.789 g/mL.
mole fraction = ?????;
molality =
??? m
In: Chemistry
1. A galvanic cell is based on the following half-reactions at 285 K:
Ag+ + e- →
Ag Eo = 0.803
V
H2O2 (aq) + 2 H+ + 2 e-
→ 2 H2O Eo =
1.78 V
What will the potential of this cell be when [Ag+] = 0.571 M, [H+] = 0.00341 M, and [H2O2] = 0.895 M?
Please show full work .
In: Chemistry
How much heat (in kJkJ) is required to warm 13.0 gg of ice, initially at -14.0 ∘C∘C, to steam at 108.0 ∘C∘C? The heat capacity of ice is 2.09 J/g⋅∘CJ/g⋅∘C and that of steam is 2.01 J/g⋅∘CJ/g⋅∘C.
In: Chemistry
74) Epoxy is a(n) ?
a) elastomer
b) thermoset
c) thermoplastic
d) composite
.
75) In tempering of steel, temperature treatments around 400 °C are used to?
a) reduce brittleness and increase ductility (toughen) by transforming martensite morphology
b) increase strength and hardness by locking in martensite structure
c) increase strength and hardness by causing lower density glass layer to form on surface
d) reduce brittleness and increase ductility (toughen) by causing martensite morphology to form
.
76) Surface carburizing of steel involves
a) burning excess carbon out of the iron carbon alloy to form steel.
b) introducing extra carbon into surface of austenite to harden and toughen surface with quenching and formation of martensite.
c) forming martensite on the surface through rapid cooling to harden and toughen surface with quenching.
d) introducing extra carbon into surface of cementite to harden and toughen surface with quenching.
Please answer all of them without guessing!!! Thanks
In: Chemistry
Use data from Appendix IIB in the textbook to calculate the equilibrium constants at 25?C for each of the following reactions.
2NO(g)+O2(g)?2NO2(g) .
Express your answer using two significant figures.
In: Chemistry
With the aid of a clearly labelled schematic diagram, illustrate the main layout of a flame atomic absorption spectrometer with continuum source background correction. Describe briefly the purpose of each component.
Your diagram should include reference to the following components:
The hollow cathode lamp The flame and burner
The deuterium lamp The monochromator
The modulator or chopper The detector
In: Chemistry
What is the effect of the following on the volume of 1 mol of an ideal gas?
(a) The pressure from 760 torr to 202 kPa, and the temperature changes from 37C to 155k.
(b) The temperature changes from 305K to 32C, and the pressure changes from 2 atm to 101k Pa.
(c) The pressure is reduced by a factor of 4 ( at constant T).
In: Chemistry
Which metal can react with an acid? Cu, Ag, Al, Au (Answer is Al) Can someone explain why?
Which of the following is the most likely to act as a Lewis Acid? PH3, AlCl3, HCN, BeO2 (Answer is AlCl3) Can someone explain why? Im assuming its because AlCl3 does not have a longe pair to donate while the rest do? |
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In: Chemistry
1) A 0.23 g sample of an unknown monoprotic acid is titrated with 0.11 N NaOH. 23.89 mL of NaOH is required to reach the equivalence point. What is the molar mass of this acid?
2) You perform a phenolphthalein titration on a 0.26 g sample of an unknown organic acid, which requires 33.78 mL of 0.1008 N NaOH to reach the endpoint.
a) What is the equivalent weight (estimate) for this acid?
b) Assume the acid is monoprotic and calculate its molar mass. Assume the acid is diprotic and calculate its molar mass. Now that you have two potential molar mass values, using the list of acids in the lab, do you think this acid is monoprotic or diprotic? Explain your rationale.
In: Chemistry
Insulin sequence As reported in 1945, Sanger reacted insulin with FDNB and hydrolyzed the resulting protein. He found many free amino acids, but only three DNB-aa
In: Chemistry
In: Chemistry
In: Chemistry