October 2022 Flashcards

1
Q

Oxygen at pressures much greater than 1 atm is toxic to lung cells. Assume a deep-sea diver
breathes a mixture of oxygen and helium. By weight, what ratio of helium to oxygen must be
used if the diver is at an ocean depth of 50.0 m ?

A

less than 1

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2
Q

discovered helium

A

Ramsay & Travers

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3
Q

Who theorized stars collapsing into blackhole as it increases entropy

A

Hawking

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4
Q

when travelling at nlex t 80 mph, a stopped car in front causes you to suddenly skid to stop. What happened to the KE of the moving car

A

All of it transferred to the internal energy of the road

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5
Q

what are sigmatropic reaarrangements in organic reactions?

A

pi system does not occur

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6
Q

titanium crystal. Unit Cell

A

4.51

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7
Q

Caffeine

A

C8H10N4O2

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8
Q

access and predict the largest and smallest peak of a mass spectrum of two naturally occuring isotopes of hydrogen

A

7.8 signal intensity

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9
Q

temperature the speed of sound in hydrogen will be same as that of speed of sound in oxygen at 100C.

A

Sqrt of kRT/M

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10
Q

different tetrapeptides can be made (a) if the peptides contain the residues of
asparagine, proline, serine, and methionine and (b) if all 20 amino acids can be used?

A

256, 160,000

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11
Q

Most oxidiezed form of nitrogen

A

Nitrates (NO3-)

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12
Q

Oxidation number of O in Na2SO4

A

-2

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13
Q

how do two free radicals react when they encounter each other?

A

They unite with covalent bond formation

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14
Q

How to differentiate alkane alkene and alkyne?

A

reaction with Br2

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15
Q

Which of the following lipis contain a ceramide unit?

A

Sphingomyelins

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16
Q

Which of the following acidic group is present in taurine?

A

Sulfonic acid (-SO2OH)

17
Q

color change of litmus paper when basic

A

blue

18
Q

which among the compounds na di mo mahahanap ang C, N, H, and O in a single compound.

A

ascorbic acid

19
Q

the diamond has a face centered cubic crystal lattice

A

9.95, 11.5, 16.38, 19.31, 20.21, 23.51

20
Q

time to reach the pond, time to flush

A

2.3 days and 21 days

21
Q

degree of deprotonation of the side chain of cysteine at pH 7.30, given that the
side chain –SH group has pKa = 8.20

A

0.126