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DAT Question of the Day Questions with 100% correct answers
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DAT Question of the DayA father's age is twice the sum of the ages of his four sons. In 30 years, the total of
the sons' ages will be twice the age of their father. How old is the father now?
a) 24
b) 48
c) 32
✅✅
d) 40
e) 36 - -d) 40
If the sum of the four son's ages is x at present, the father's age is 2x. In 30 years,
the total of the son's ages will be x+4×30=x+120, whereas the father's age will be
2x+30. Therefore, x+120=2(2x+30), which yields x=20, and hence, the father's age
at present is 2x=40.
If the temperature drops by 18o Fahrenheit in a given day, how much did it drop in
degrees Celsius?
a) -14
b) 10
c) 32.4
✅✅
d) -7.78
e) 25.2 - -b) 10
The ratio of "change in degrees Fahrenheit" to "change in degrees Celsius" is simply
9 to 5, and therefore, (18×5) / 9 = 10. If you were converting a temperature of 18o
Fahrenheit to degrees Celsius, then it would be ((18-32) × 5) / 9 = -7.78o Celsius.
Which of the following will not dissolve in water?
A. Salt, NaCl
B. Ethanol, CH3CH2OH
C. Benzene, C6H6
✅✅-C. Benzene, C6H6.
D. Hydrogen chloride, HCl
E. Acetic acid, CH3COOH -
The law of solubility is that "Like dissolves Like", that is non-polar solvents dissolve
non-polar substances and polar solvents dissolve polar and most ionic substances.
Water is a polar solvent thus:
Salt, NaCl - ionic and very soluble in water, sea water.
Ethanol, CH3CH2OH - polar molecular (-OH) will dissolve in water, beer/wine/spirits.
Benzene, C6H6 - non-polar molecular will not dissolve in polar water.
Hydrogen chloride, HCl - polar molecular will dissolve in water, hydrochloric acid.
Acetic acid, CH3COOH - polar molecular (-COOH) will dissolve in water, vinegar.
,Which of the following structures of the skeletal system is innervated?
A. Hair
B. Nails
C. Cartilage
✅✅-E. Haversian canals
D. Osteoclasts
E. Haversian canals -
Innervated refers to the structure having nerves and blood vessels that run through
it. Nails and hair are consider dead/dying cells and would not have blood vessels
that run through the exterior nail structure. Cartilage is not innervated which
attributes to the long healing time of sprained joints. Osteoclasts are cells that help to
break down bone cells and these cells themselves do not have blood vessels or
nerves. The Haversian canals are a network of opening in the bone that allow for
nerves and blood vessels to weave in and out of the bone.
Two trains are approaching each other from opposite directions with the speeds 10
miles per hour and 20 miles per hour, and heading for a collision. If they are a
quarter mile apart, how long will it take for them to collide?
A. 45 seconds
B. 20 seconds
C. 30 seconds
✅✅-C. 30 seconds
D. 40 seconds
E. 1 minute -
The speed at which the two trains are closing the gap between them is 10 + 20 = 30
mph. At the is speed, it will take (0.25/30) × 3600 = 30 seconds to close a gap of
0.25 miles.
Which of the following statements is correct?
A. High molecular dipole moments are characteristic of nonpolar molecules
B. Polar solutes tend to be more soluble in nonpolar solvents
C. The polarity of a molecule is dependent on its 3-D structure
D. All polar molecules are capable of hydrogen bonding
✅✅
E. London dispersion interactions are usually stronger than dipole-dipole
interactions - -C. The polarity of a molecule is dependent on its 3-D structure
A molecule's dipole is an electric dipole with an inherent electric field (not be
confused with a magnetic dipole which generates a magnetic field). Molecules can
have dipole moments due to non-uniform distributions of positive and negative
charges on the various atoms. For diatomic molecules there is only one (single or
multiple) bond so the bond dipole moment is the molecular dipole moment, with
,typical values in the range of 0 to 11 D. For polyatomic molecules there is more than
one bond, and the total molecular dipole moment may be approximated as the vector
sum of all individual bond dipole moments.
If an unknown compound is found to have an empirical formula of CH4, which of the
following is the molecular formula if the molar mass was determined to be 128
g/mol?
A. CH4
B. CH12
C. C8H12
✅✅-D. C8H32
D. C8H32
E. C12H16 -
To determine the molecular formula using an empirical formula, the ratio of the
molecular mass to the empirical mass must be calculated. Dividing the molecular
mass of 128 grams by the empirical mass of ~16 grams (C = 12g + H = 1g, but there
are 4 hydrogens in the compound) gives you approximately 8. This indicates that the
empirical subscripts must be multiplied by 8 to result in the molecular formula of the
unknown compound, C8H32.
Which of the following molecules is amphipathic?
A. water
B. glucose
C. steroids
✅✅-E. phospholipids
D. triglycerides
E. phospholipids -
An amphipathic molecule has both a hydrophilic ("water loving") and a hydrophobic
("water fearing") region. Water is hydrophilic, whereas a triglyceride (or lipid) is
hydrophobic. Glucose is also hydrophilic. Steroids are derived from lipids and also
would be hydrophobic. A phospholipid is made of a phosphate group (hydrophilic)
and two fatty acid chains (hydrophobic) and is amphipathic.
From a group of 5 men and 7 women, in how many different ways can a team of 2
men and 3 women be formed?
A. 95040
B. 792
C. 350
✅✅-C. 350
D. 4200
E. 18 -
, 2 men can be picked from a group of 5 in (5|2) = 10 different ways, and 3 women
can be picked from a group of 7 in (7|3) = 35 different ways. Therefore, the total
number of ways a team can be formed is 10 × 35 = 350.
Extended explanation: If you got D. 4200, you interpreted this problem as a
permutation, not as a combination. We do not care what order the men are picked in
or what order the women are picked in, all we care is that there is a team of 2 men
and a team of 3 women.
Permutation equation:
P(n,r) = n! / (n-r)!
Combination equation:
C(n,r) = n! / r!(n-r)!
Where n = total number of the group and r = the number of people we want. Hence,
n = 5 men
r = 2 men
We have 10 total possible combinations using the above formula.
The same goes for women.
n = 7 women
r = 3 women
We have 35 total possible combinations using the above formula.
Multiplied together, we have 350 possible combinations.
How many degrees of unsaturation are present in the anxiolytic drug Valium
(diazepam), molecular formula C16H13ClN2O?
A. 8
B. 9
C. 10
✅✅-D. 11
D. 11
E. 12 -
Degree of Unsaturation (or index of hydrogen deficiency, IHD), or rings plus pi
bonds, lets you determine the number of rings, double bonds and triple bonds
present in the compound if the molecular formul is known. It does not give the exact
number of rings or double or triple bonds, but rather the sum of the number of rings
and double bonds plus twice the number of triple bonds.
Degree of Unsaturation = C - (H/2) - (X/2) + (N/2) +1 (C=#carbon, H=#hydrogen,
X=#halogen, N=#nitrogen)
= 16 - (13/2) - (1/2) + (2/2) + 1 = 11
Extended Explanation
First use the saturated formula CnH(2n+2) which will get you to C16H34
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